You’re probably registered on at least one forum. And you’ve no doubt seen that in your forum profile, you can add your favourite Instant Messaging (IM) profile details, and other users can see if you’re online. You in turn, can see who else is online as well. Well what if you want to add that status indicator to a website you run? Here are a series of PHP classes that can detect the online/offline status in all of the major IMs.

Note:  I did’t test any above classes.  Do it in your own risk.  I got this info while i googling around internet. Comment me for anything.