I am currently trying to set-up a LAN party for myself and a few of my friends. My biggest obstacle however, is the fact that all of my best MP games (TF2, CS:S, Borderlands etc...) are all on Steam, which only one of my friends has. What restrictions apply when you try to run the same Steam account on multiple computers at the same time? Does it log you off comepletely, or merely block online gaming? Also, do said games (TF2, CS:S, and Borderlands), operate on Peer to Peer for LAN or are they server-based?