[B]multiple gtalk with out any software
1. Right-click GTalk shortcut and select Properties.
2. The shortcut properties dialog box as shown below should popup.
3. Just add /nomutex to the existing text Eg: "C:\Program Files\Google\Google Talk\googletalk.exe"/nomutex
and if you see like this "C:\Program Files\Google\Google Talk\googletalk.exe"/startmenu
then just avoid that start menu and add nomutex okies
then it will works.......
4. Now you can launch multiple windows and use different ID's.