Yahoo! IM
 

I was curious if there is a way to view someone that's on Yahoo! Instant Messenger while they are in invisible mode.

Far as I know, nope, not nowadays.

In the old days when IM was in it's infancy there were numerous ways to get any and all of anyone's IM info but things are a lot tighter now.

Best I can suggest is - <b>if</b> the person has cable/adsl <b>and</b> a static IP, you could ping their IP to know if their comp is switched on.

Or just learn to trust a little :-)