I use the sms forwarding service/reply to emails from facebook and have them get sent to me. Simple, works on any phone, but not sure it works for casual chat and new conversations - you can tell how much I use it...

Doesn't "facebook" or "mysocials" work?

I think it also used (may have been closed down/may still work?) to support that jabber xml format thing that google-talk uses too (or might be misremembering).