If you’ve got many Gmail accounts and don’t want to keep logging on and off them every time you switch, a simple command line parameter in the Google Talk shortcut can solve your problem.

Doing this is very simple. Create a new Google Talk shortcut on your desktop, leave the original intact.

• Right click on this shortcut and choose Properties. The Target box will show you the path of the EXE for Google Talk - something like “C:\Program Files\Google\Google Talk\googletalk.exe”
• Change this to: “C:\Program Files\Google\Google Talk\googletalk.exe” /nomutex

and click OK.

Now you can login with as many Gmail accounts as you like.

Enjoy! :D