Here's an interesting idea for GTalk, Yahoo! Instant Messenger or Windows Hotmail Live Spaces Instant Messenger 8.054... the ability to customize the "new IM" sound if the IM is a single-word "yes" or "no"
We use Y!IM a lot here in the office for communication. I have to change the sound effect really frequently because after awhile, it gets annoying (because I get a lot of IMs) and I start resenting whoever's IMing me. I've finally settled on the "fwop" sound which sounds like an arrow flying past me. It would be cool if someone replies "yes" or "no" if I could pick a different sound.
Would make me even more productive.