By this trick you can easily know if a person is invisible or not.
just follow these steps:
Step 1:
Login using G-talk. (not in gmail or orkut)
Step 2:
Find the person in the list whom you want to check if invisible.
Step 3:
Open the chat box and select 'Go off the record' option from the popup list.
Step 4:
After that type some message and send it to him.
If the message shown in yellow box here is displayed, then he is presently offline. Otherwise you will get a message telling about your 'off record' situation.
