If you want to find out if you're blocked without annoying the shit out of the person you're checking and keeping in mind the privacy settings of the people you want to check then just use one of two sites. Each one will give you the current nick minus the personal message IF their privacy settings allow their status to be seen.
Also works for Yahoo, AIM, etc
Allows input of 8 email addresses at one time
NOTE THAT NEITHER WILL WORK IF THE PERSON HAS THE PRIVACY OPTION "Only people on my Allow List can see my status and send me messages" SET !!!
This avoids ticking anyone off any more than you already have that got you blocked in the first place by using something that's just going to get in their face.
The ONLY real bonus to these particular sites is if you CANNOT sign into MSN and are wondering if someone who DOESN'T have you blocked is on it will let you know.