Hi Rahul & Emil!
Thank you for the very useful information. Alas, I'm not a programmer,
so I can't write the interface to iimport all of jingle. It's
surprising that about three years after Google Talk was launched there
is apparently still no way to use it with voice under Linux ( except,
perhaps, by using some third-party gateway.)
Perhaps, it would be better to try sip for voice chats!