Originally posted by Makuta_Death
Hey, well I know a way to sign into multiple MSN's at one time, try to install StuffPlug v3 (I'm not sure if it works with the new MSN Beta works fine with MSN plus though) Click the StuffPlug icon, click general I think it was in the Options, and click Polygami (Sorry for typo's) Then open MSN normally with your other MSN opened, it should open it and let you log in fine.
Windows Live Messenger is no longer a beta, it's a full release.
Messenger Plus! Live offers a Polygamy feature which works fully, but this is more of a workaround for what the OP is after.
As for the original question, yeah, you can't talk to all of those 990 contacts. If you have Messenger Plus, use the Contact Cleanup feature to see those who have deleted you...or those you haven't spoken to for months and clear some out