If you’re up late tonight, go and look at I’m on Google Talk right now. If you can get things to work, you can “GoogleTalk” me at firstname.lastname@example.org.
Update: David Richardson from Calgary just “GoogleTalked” me, using his GMail account to login to the talk.google.com server. We were able to have both a regular text chat as well as an audio chat, all of which was happening Jabber-only, as David switched off his regular iChat account. Neato.