Tweet Chimes lets you listen to twitter. Check it out:
When you log in through Tweet Chimes, the software listens in to twitters streaming api sample feed. Every time it comes across a letter, word or smilie you've set up, it plays a sound. Simple as that.
By clicking this link:
Or download it here: (soon)
Or download the source here: (soon-ish)
If anything doesn't work (and that's quite likely), email me at Daniel[at]14lines.com and I'll fix it.