Referring to your question:
"Why do you want somebody to talk on google talk from Tigase through google account? Isn't it simpler to use just google talk service for this?"

This is quite useful, and I am extremely interested in this usecase. For me it looks very natural that there are many XMPP servers out there, and I can talk to somebody sitting on any of those servers. I'd really like to see it functioning like the e-mail. I send an e-mail using my SMTP server, and my message gets to any addressee, independent of the mail provider. So it's actually the server who is dealing with the message sending to other servers, not me (client) connecting to different servers.

Therefore, I would certainly use Tigase (my XMPP server) to talk to other servers, e.g. GTalk, in order to dispatch messages to the person I am reaching out. How do we achieve this??? Looks like it's solely a matter of configuration, isn't it?

Evaldas

PS. By the way, notifications from forum-2@srecv.tigase.org don't work for me...