Ambrosia has released Snapz Pro X 2.5.2 to fix an issue with accurately capturing the precise pixels of a selection and bring back support for several styles of image borders (which was excised in version 2.5). The update also improves the reliability of movie encoding, improves compatibility with both OS X 10.8 Mountain Lion and Retina displays, and adds Chinese and Russian localizations. ($69 new, free update, 15.8 MB, release notes)
Go Back and Forth Fast in Preview
If you're reading a PDF in Apple's Preview software, and you follow a bookmark or an internal link to move around within the PDF, you can quickly return to where you were by pressing the keyboard shortcut Command-[ (that's Command-Left Bracket). Or, you can choose Go > Back.
The command works iteratively, so you can go back to just the previously viewed page or if you issue the command again, to the page before that, and so on. There's also an equivalent Go > Forward (Command-]).