Araxis Merge is the two- and three-way visual file comparison/merging and folder synchronization application. Use it to compare, understand and combine different versions of source code, Web pages and other text files, or even text copied and pasted from another application (e.g., Pages or Microsoft Word). Merge integrates with Time Machine, so you can compare older versions of files.
Jitouch is an application that expands the set of Multi-Touch gestures for the new MacBook and the new Magic Mouse. These thoughtfully designed gestures will enable you to perform frequent tasks more easily such as changing tabs in Web browsers, closing windows, minimizing windows, changing Spaces, and a lot more.