how to detect invisible yahoo messenger users?
These are a few sites which will help you find out if an user is invisible in the YM or not. I have personally checked out these sites and many are working fine. Request readers to post your comments.
http://www.buddy-spy.com/
http://www.xeeber.com
http://yahoo.4tvn.com/
http://www.invisible.ir/
add this too
Yahoo Status Checker at http://www.yahoostatus.org