Normally, Matt Neuburg looks at all the text management and snippet keeping utilities for TidBITS, but back when AquaMinds' NoteTaker and Circus Ponies' NoteBook were coming out, he dove into NoteTaker (see "Take Note of NoteTaker" in TidBITS-677) and I opted to take a look at NoteBook. The decision was essentially random at the time, but since then I've become familiar with, and fond of, NoteBook, and the few times I've taken a peek at NoteTaker, I've remained happy with my choice of NoteBook.
Reams of Ruled Paper -- NoteBook is, like so many of these programs, designed to make it easy to store, categorize, and retrieve information. It's built, as you'd expect, on the notebook metaphor, with pages grouped into sections indicated by a tab (which you can Control-click to jump to any page in that section). You can add another layer of hierarchy by creating multiple files, of course, but I prefer keeping everything in a single NoteBook file for simplicity's sake. Individual pages and entire notebooks can be encrypted for privacy.
Information on pages is organized into cells, which can contain text, graphics, audio, video, URLs, files, or aliases to files. You can organize cells in standard outline fashion, with multiple levels of hierarchy. Cells can have dates (creation, changed, due) associated with them, along with action item checkboxes that, when checked, can cause the cell to become greyed out. You can also assign styles to different outline levels, style text independently within any given cell, and set cells to be numbered. For additional metadata, you can assign keywords and stickers (think of them as little graphical keywords) to cells, and you can mark them with a highlighter tool.
I can't say whether NoteBook would meet Matt's standards for outlining controls; it seems to do almost everything I want, and I don't do enough with outlines to care all that much. My only irritation, and I'll explain why I do this later, is that you can drag a cell around to move it, but you cannot drag multiple cells at once; for that you must use cut and paste.
You can add data to a NoteBook page in a wide variety of ways. There's nothing wrong with just typing, of course, but you can also paste in text or graphics, and you can drag data in from other programs. To create a page that collects bits of related text, the easiest thing to do is to assign a "clipping service" to a page; from then on, you can select text in any Mac OS X application (not Classic, of course), Control-click the selection, and choose the desired NoteBook page destination for your clipped text. NoteBook also has a Media Capture capability for importing multimedia files directly from cameras or other devices, along with a Voice Annotation feature for adding voice notes; I haven't particularly used either of these features.
To find information you've stored in NoteBook later, various options are available. NoteBook maintains a number of indices automatically, so it's easy to see entries by Text, Capitalized Words, Numbers, Internet Addresses, Highlighting, Keywords, Stickers, Attachments, Discarded Attachments, Creation Dates, Change Dates, or Super-Find Results. Each of these indices (really a concordance) is a separate page showing lists of cells that match the built-in searches. So the Capitalized Words index, for instance, appears as a big list of capitalized words, organized alphabetically; clicking any word expands its outline level to reveal the actual cells containing the clicked word, and clicking the bullet next to one of those cells takes you to the page containing that cell. You can of course perform normal searches as well, limiting the scope to the selection, to a page, or to the entire notebook.
Despite all that searching power, I seldom use it because I've organized my pages into tabs, and each tab page is a table of contents for the pages inside the tab. Most of the time, I know exactly where the information I want is, so I just go straight there without worrying about a search.
As far as getting information out, you can export in a variety of formats and print; I've used these features only occasionally, since my goal is to keep information in NoteBook, not to use it as a staging area for creating other types of documents.
My Usage -- That's how NoteBook works. I haven't examined large numbers of other snippet-keeping programs to know exactly how they compare, but I will say that those I have looked at haven't floated my boat. NoteBook does what's necessary for my purposes, and it does it in an easy and elegant way. So what are my uses? Perhaps you'll get a sense of what NoteBook could do for you if I describe what it does for me.
To Do List: The reason I keep NoteBook running all the time is that I've taken to keeping my to do list in it. You may have noticed that I didn't talk about any automatic moving of unchecked items or pop-up reminders or anything like that. Those approaches don't work for me - I always end up ignoring them. Now Up-to-Date has a fine to do list capability, moving unfinished items along each day and reminding me nicely that they're not done. But I've learned to ignore it entirely - it does too much for me. In NoteBook, I've created a tab for To Do List, and inside that, I create a page for each week. On each week's page, I have top-level outline entries for the day of the week, and second level entries for each individual item. Most have action item checkboxes, though some items are just reminders to myself about appointments, and those don't get checkboxes. Sometimes a second-level item will end up with notes underneath it (such as when I have a product briefing call with an industry company). Each day I manually move all the unfinished items to the next day (hence my earlier irritation with being unable to drag multiple cells), and each week I create a new page and bring forward everything that's undone. By forcing myself to manage the to do list manually, I never find myself ignoring it for weeks or months, as has happened with every other approach I've tried.
Process Minder: As I've started to move to Web Crossing for our primary server, and as we've built up numerous processes for Take Control, keeping track of exactly how I perform certain tasks has become onerous. I just can't remember how I deal with certain tasks that I perform relatively infrequently, and I also want a record of what I'm doing in case I need to train someone else to do the same tasks. A number of my pages are thus just sets of steps and notes to myself about how I perform a given action. They're invaluable at this point - I would make far more mistakes and forget parts of processes entirely without them.
Internet Research Snippet Keeper: Every now and then I need to research something where I want to collect text from a number of Web sites and email messages, and I use clipping services in NoteBook to facilitate that.
Post-it Note Eliminator: Like many people, I write things down on little bits of paper all the time (not Post-it notes, actually, but old pages from daily calendars, which I love for that purpose). They're great for highly temporary information, but those that contain more permanent notes tend to collect and breed on my desk, so every now and then I go through them and transcribe everything into NoteBook, where I can rest assured that the information won't be lost, and where I can ignore it happily without cluttering my desk.
Project Notes: Sometimes, when I'm working on an article or a talk, I'll need a place to store some notes before I start writing or work up a presentation in Keynote. I've used NoteBook to store those notes in the past, but I've never been wildly happy about it since it feels odd to enter information into NoteBook that I know is temporary; once I write the article or prepare the presentation, the NoteBook pages are utterly useless. I could delete them, but that seems wrong too, somehow.
Minor Quirks -- I've been using NoteBook for quite some time now, and most of the annoyances I've had with registration numbers, crashes, moving files between Macs, and so on have been resolved by small updates along the way. My remaining problems are small. NoteBook doesn't remember its window position on my second monitor, and it won't let me move a window into the area that, if it were on my main monitor, would be occupied by the menu bar. Then there's the inability to drag more than one outline item at a time. You can link a text in a cell to another page in NoteBook, which is handy (I use it in my process pages when a process can be broken down into independent chunks), but you can't link from a cell to another cell.
These niggles aside, NoteBook has proven itself a worthy tool. Until I came up with my to do list approach, I couldn't see how I'd use NoteBook sufficiently to keep it in the front of my brain, but since I started forcing myself to maintain my to do list manually, I've found additional uses for the program, and I've also found myself appreciating what it does for me. There's no question that other programs can perform roughly the same tasks; Matt has reviewed oodles of them in TidBITS. But given a choice of any of them, I'll stick with NoteBook.
NoteBook 1.2 costs $50; a free 30-day demo is available as a 7.7 MB download so you can see if it meets your needs. It requires Mac OS X 10.1 or later.