DISQUS

1. Apple Macbook Pro [running 10.5.2 on a 2.4Ghz Intel Core 2 Duo with 4gigs of RAM thanks to a special newegg.com had last month on the memory.....next up will be swapping out the HD for a faster/larger one]
2. Adium - [Free instant messaging software that connects my gchat/aim/msn accounts into one]
3. Xbox 360 [Not just for the gaming, but I also use it to stream video from my media server in HD via my home network]
4. Firefox [With Firebug + Yslow (developer plug-ins), as well a few other plug-ins to block cookies/ads/pop-ups]
5. NetNewsWire [My RSS Reader of choice... now free, i have all my feeds categorized, including twitter/del.icio.us additions/comments]

i felt like a traitor even going from POP to using imap...

OG 2.0?

now would kayaking count if while waiting for the 3rd member of our group to finish getting his gear all together I and my buddy were talking about twitter... (even resulting in him pulling out his iphone to show his fav. twitter app)? I mean, 2 minutes later we were in the water actually kayaking (although my friend would have brought along the phone if they ever start offering completely water-proof versions of it)....... :)
I usually twitter when i'm waiting for something to render/upload/finish cooking... i.e. bored.
So short answer to your question is: Everything.
A better question in my case would be: what are you doing while twittering... although i wouldn't ask that on a post because although i know people use their phones two twitter while on the can... i really just don't need to know that...