So Google Talk has been covered to hell now, but the best entry I have found is this one called Smsh which details how to connect to Google Talk with any Jabber client. I havent even bothered downloading the client because Skype serves me well right now, but I'm interested to find out what protocal there using for voice over ip.
I got a feeling that Google Talk is only the start of things…. it would be really useful if google added a bot for searching via im. Till then, I'm currently using it under the username – cubicgarden if you want to drop me a test im and confirm it works. You can find my Gaim settings here on Flickr.