1. A buddy list pruning method for instant messaging system performance enhancement, the method comprising: comparing buddy list name entries in a buddy list to entries in a network directory used to authenticate users into a network supporting the instant messaging system; characterizing selected ones of the buddy list name entries as either invalid where a buddy list name entry cannot be matched to an entry in the network directory, or valid where the buddy list name entry can be matched to an entry in the network directory; and, performing presence awareness only on valid buddy list name entries in the buddy list.