An app note from Intersil on utilizing CAT-5 cable for SXGA video transimission. Link here (PDF)
The goal of this application note is to present the most current design methods for transmitting high bandwidth SXGA video signal over long distances of CAT-5 cable (300m or more). The enormous cost benefits of CAT-5 cable will also be discussed; for instance, the average cost of a 100m of CAT-5 cable is $20 while the average cost of a 100m of Coax Cable could easily exceed $240. Furthermore, wiring is reduced from a bulky hard to manage bundle of 3 cables to 1 easily pulled cable. Additionally, CAT-5 cable has a 4th twisted pair available, which can be used for KVM signal, audio, timing or control signal transmission.