After adding support for OS X 10.9 Mavericks in its version 5.0 release, TinkerTool 5.1 from Marcel Bresink is now sandboxed for better security. The under-the-hood customization system utility also does away with the Login Items pane as it’s no longer useful for Mavericks, differentiates between the actual Lucida Grande typeface and the new screen system font introduced with OS X Mavericks, reinstates the preference setting that enables you to copy text displayed by Quick Look (for 10.9.1 and later), and reduces storage space used by the preference reset feature. While the latest version of TinkerTool requires 10.9 Mavericks, Bresink continues to offer older versions of TinkerTool for those running previous big cats, all the way back to 10.1 Puma. (Free, 3.9 MB, release notes)
Avoid Simple Typos
If, like me, you find yourself typing 2911 in place of 2011 entirely too often, you can have Mac OS X (either Lion or Snow Leopard) fix such typos for you automatically. Just open the Language & Text pane of System Preferences, click the Text button at the top, and then add a text substitution by clicking the + button underneath the list. It won't work everywhere (for that you'll want a utility like Smile's TextExpander), but it should work in applications like Pages and TextEdit, and in Save dialog boxes.