someone knows how can be done?

PIC -> http://img524.imageshack.us/img524/1850/itsposs...

nobody?

Bookmark this javascript:

javascript:(function(){javascript:window.open('http://talkgadget.google.com/talkgadget/client','gtalk','width=250,height=600,location=no,toolbar=no,status=no,menubar=no,hotkeys=no,directories=no,resizable=yes,scrollbars=yes,screenX='+(screen.availWidth-410)+',screenY='+20);})();
Run it and resize your windows vertically :D

PIC -< http://img130.imageshack.us/img130/4462/gtalkwi...

i tried to embed this flash-GTalker to orkut but i failed - hope it helps:)

P.S : DeviantART Orkut style - http://userstyles.org/styles/2837

Well i dont know how the gmail chat had been integrated into orkut. I will try to give a look. You can have a look at http://userscripts.org/scripts/show/11849 to integrate gtalk gadget into orkut.
If you want it simply the way as Tanel suggested all u need to do in your firefox is bookmark http://talkgadget.google.com/talkgadget/client and while adding it as abookmark select Open bookmark in sidebar.