Conversation threads would be a definite benefit in Twitter, although I can't see how they'd implement it now without everything going crazy.

I stopped using Twitter because the signal-to-noise ratio became too much for me to handle. At one point, I disabled Growl (a system-wide notifier for OS X) for Twitterific but it was still getting on my nerves.

I don't know about a temp-IM feature--it's not what Twitter is about, and it's quite a tough crowd to deal with given the ubiquity of the more standard instant messaging protocols and online tools like chatterous, meebo or mibbit (assuming I spelt all those right).

What I'd like to see is Twitter for groups: I have 2 twitter followers who are working with me on something. Let me make a private group and Twitter away.

What problem does Twitter solve that IRC has? :/

>What problem does Twitter solve that IRC has?

Ego.

Fragmentation, and Chanserv is a steaming pile of shit. That's all I can think of. (But Jabber solves those problems better.)

I've tended to log into IRC just to see what goes past. Much like I do when I've logged into Twitter.

I can't IRC from my phone; even mibbit.com doesn't work right.

What model phone is it?