There's #news.yc on the EFnet IRC network, and it has a few regular visitors.

http://www.efnet.org/?module=servers

Move it to Freenode =D

Hi everyone, - I added a room on Meebo which might faciliate some real time conversations. See you all there!

If you'd care to use a non funded-up-the ying/yang chat startup that has mobile support: http://mychatlog.com/chat?channel=ycombinator

We really need an official chat room for this sort of thing. IRC would work best.

Then again, maybe no chat room would work best, too.