I may have missed the point, but here goes...
If you know what you\'re doing, playing PS on a network is no problem, as is using any network application.
If I\'m not mistaken, azeazezar is talking about using a DMZ computer, which basically means a computer outside the network proper (i.e. beyond a firewall/router) to get around difficulties such as the one you\'re speaking of. DMZ computers are huge security risks though, and are usually unnesscary (barring the occassional unique network configuration).