Gefen is not a famous company but they are one with an interesting idea that they’ve just made real.  They will sell you a box that can extend a HDCP compliant signal along CAT6 cable of up to 1920x 1200  resolution as far as 200′.  It can send a 2560 x 1600 using a pair of CAT 6 cables, though that signal does not seem to be HDCP compliant.  The only down side is the price, at $1300 this is not something you buy because it is neat, but because you really need it.

"CHATSWORTH, CA – The leader in digital connectivity announced the release of its new extender for professional computer systems using dual link DVI graphics. The DVI DL CAT-6 Extender offers a plug and play method of signal extension that guarantees a lossless video transmission with zero signal dropouts.

The next generation DVI DL CAT-6 Extender delivers uncompressed high resolution video to any remote display up to 200 feet (60m) in distance over two industry-standard CAT-6 cables. This is a substantial advantage over previous solutions, which required an add-on booster using more expensive cabling to handle distances beyond five meters. "

Here is some more Tech News from around the web:

Tech Talk