Here is a small selection of projects I have worked on in the last few years.

Rockstar
Rockstar is a wrapper for the audioscrobbler v2.0 (last.fm) web services. This gem includes scrobbling with the new api.

Chrome Passwordmaker Pro
A chrome extension based on passwordmaker.org . Create unique passwords for every webpage using a hashing algorythm.

Detinyfy
Expand shortened urls from services like bit.ly.

Git commit notifier
Send beautiful html mails for each git push.

TV-Browser
An EPG for your Desktop.

More projects can be found on Github.