Many people normally go to invisible mode when they don't want to chat with everyone or when they are busy with work . You know some one's ID and you want to check whether they are online or not ?? How will you detect a invisible user on Yahoo Messenger ??
Many methods are already available on the net at this moment like using Doodle IMvironment, Shealth settings check, Voice Chat and Conference Invitation ( You can use these methods in yahoo messenger only and no need to use a 3rd party site or program ) . Apart from these there are some sites and programs that lets you know directly about the person is invisible or not . I'm discussing few here :
(1) Invisible.ir - Simply the best site in this category that works each time. Must try this Fast And Accurate Yahoo Invisible User Detector. You can also check multiple Yahoo users at once and detect a users invisibility by just giving his/her main Yahoo ID.
(2) Buddy Spy - This is not a site, but Buddy Spy is a little program that you can download and install on your comp. It suggests that it’s “simply the best in invisible detection”! I’m not so sure about that, but I’ve heard it works most of the time. But looks a bit complicated to work on.
(3) Invisible Scanner - Never tried it , but still it claims to do the same. Go check it yourself :)(4) Xeeber.com - Frankly speaking I tried it many times, but each time it just says SERVER BUSY. Not much impressed with it.
If you have any other great way to find those hidden creatures , then post it as a comment . Njoy !!!