I have an open source project now: stagefright, a playlist generator/randomizer. Certainly it's nothing new, but I wrote my own because I had specific requirements in mind, and because I wanted to write and maintain some perl code. The script is presently driving my icecast stream. I also spent quite a bit of time profiling the script with smallprof, because the script needs to run fast, or people will be stuck listening to silence. My typical usage cases currently execute in under 0.5 sec. O'Reilly's Perl Cookbook has also been immensely helpful.
Putting my project on sourceforge gave me a cvs repository with viewcvs, a place to release files, and a place to track bugs. While I could set all of this up on my own server, sourceforge also provides the possibility of finding users, and possibly the occasional suggestion or patch.
A couple features I planned to do, which I thought would take a week or more to finish, got done in 1-2 days. Somehow, the thought of others watching my project, wondering why it would take me so long to implement a simple feature, prompted me to work much faster.
So I guess I'm an open source exhibitionist.