ZoomIt is a port of a Windows tool that lets you zoom and draw on the screen while doing presentations. Looks cool and is free/open source.
Gloomberg is an open source finance terminal. Pretty neat looking. Not sure I have any use for it.
Marco Arment wrote about his new app Unforgetful, which does sound like a thoughtful new take a task management. Task management is a hard space to break into (very crowded), but there are some new ideas here.