People often activate the invisible mode for one reason or the other. The may be busy with some important task and want to chat only with those who they want to or they may have come online just to check out few important e-mails. Whatever may be their reason to stay invisible, you can always find out whether they are really offline or just pretending to be offline.
The Trick :
Open and login into your GTalk account and click on the person who you want to confirm as offline or invisible. Once you are in the chat window, click on the down arrow and select “ Go off the record” .
GTalk will display a message “You are now off the record (from now on, chats with ***** will not be saved in *****’s Gmail account or yours)”
Now type your message to the person. After you click enter there are two possibilities
Possibility 1 . GTalk displays a message in red color that “xxx@gmail.com is offline and cannot receive your messages right now “. This indicates that the person is really offline and its no point sending messages right now.
Possiblity 2 . GTalk does display any messages and goes on with a normal chat window. This indicates that the person in not offline but is simply using the invisible mode.
I think now you can catch any one who is trying to hide from you on Gmail or GTalk