Yahoo messenger provides us a option to be invisible to all the users are to some selected users.This feature is not available in Gtalk.Yahoo provides this feature at the same time it also provides the trick to find out if some one is avoiding us are they are too busy to talk to us.
STEPS
1) All you need to do is click the above picture which takes you to that site.2) Enter the Yahoo Id of the person whom you want to check whether he or she is avoiding you are not.
3)You can enter a id and it immediately detects whether the person is online or offline or whether he is in invisible mode.