Closed Circuit Computer Television?

Modern Fix asks: "I work at a small business with about a dozen employee's slaving in half a dozen offices. We're all relativily computer and media savvy, but have all desired for one thing: a networked television channel we can all use for project work and multi video playback. Basically, we've got a television in each office, and an extra pentium 3 computer system. Is there a way (perferabbly wireless) to configure that computer to display media (divx, etc), general computer (powerpoint, etc) work and whatever we have as a source input onto all of our televisions?"