A nice little application that provides an effective, light-weight journal keeping capability. I like the way you can edit entries in Wiki-style markup, and can export to HTML, PDF, etc. The search feature works well. The annotation/tagging feature is a bit strange and doesn't seem all that useful, but it doesn't get in the way of the basic functionality which is quite good.
A comic strip downloader and archiver.
A Qt-based multimedia player.