If you chat very frequently with one of your friend then now you can make GTalk chat shortcut on your desktop. It will initiate a chat with only one click. On click it opens a chat window where you can chat with your friend. But unfortunately this trick works only in window XP, NT in window vista.

Here are steps to follow:

1. Right click on your desktop and go to New > Shortcut.
2. In create shortcut window, type gtalk:chat?jid= username@ gmail.com. Where username is gmail id of your friend.
3. Click ok.

Its done.

You can also make shortcut to call your friend for that you have to write gtalk:call?jid= username@ gmail.com.