I had a great experience at ZakSpeed Bellville yesterday. I was looking to run 40m of HDMI cable from our lounge to the family room. If you've seen the price of HDMI cables you'll know I was dreading the cost. That, and technically there is a limit on the distance an HDMI cable can successfully carry the signal. Category 1 cables of high quality (thicker wire) are generally limited to 15m.
Luckily ZakSpeed had a solution. The little aluminium blocks below take the HDMI signal and convert it to run over ordinary networking cable, which is a lot cheaper than HDMI cable (think R5/m vs. R50/m). These blocks are spec'd to carry the signal upto 50m using high quality (Cat 6) networking cable. They didn't have stock of Cat 6, so offered to try Cat 5 and test it for me. Unfortunately that didn't work very well (except for low resolutions - which have lower bandwidth requirements).
Today I got the 40m of Cat 6 from them and that does work perfectly- excellent! One more advantage of these devices is that the transmitter is also a splitter, so you can watch the same HD stream on two devices. Here's the link to the device on ZakSpeed's website: http://goo.gl/SMtHJ
They also have 1-to-3 extenders (watch on 3 distant tv's), 4x2 matrix switches (4 inputs, two outputs selectable from any of the inputs), and just about every combination in between.
Note: They also give you great trade discount if you bring your company proof documentation.