Quick questions such as "How can I search history in bash?" or "How do I copy to system clipboard in Vim?"<p>What are the platform options for this <i>very fast</i> question and answer service? Not something like StackExchange. More along the lines of IRC. I've also considered Yammer, Socialcast and Campfire.
I telecommute for a company that uses Skype for everything - we have a company-wide group chat, and separate group chats for developers, marketing, etc. This makes it easy to throw out a quick question or see who's online at any given moment.<p>Are you strictly looking for web-based software?
My last job hosted an XMPP server, and we also had a locally hosted pastebin. On the XMPP server we hosted chatrooms, so the IT people would hang out in one, and the software devs in another.<p>What I use right now is Microsoft Lync (aka Communicator), since we're on the MS stack for infrastructure. The nice thing about that is you can click the "Share Desktop" button if you needed to show something you have. I don't know if it supports predefined chatrooms, but you can get multi-user chats by dragging people into IM conversations.