Can this be done? How does one do it?
I'd like to set up a projector in my living room to watch the Olympics, but use the HD source (Cable Box/DVR) I have in my media room as the source.
Yes, sort of. One way, not wireless, is to use a Netstreams MediaLinx encoder and a Netstreams ViewLinx decoder. This sends data over your existing CAT 5 cable-based network. List price is about $5600 for the pair. Ouch.
In the wireless world, you might look at pairing a D-Link Xtreme N Duo mediabridge with your cable box or satellite receiver. The D-Link device will connect wireless to your network. Then at the other end, a Linksys DMA 2200 Media Center Extender would wirelessly receive data from your wireless network and be wired to your TV. Although these both use 802.11n, since 802.11n isn't completely standardized I don't know if this will work.
CEO and Editorial Director, Nextscreen LLC
Avocent makes Wireless HDMI sender/receivers, but they are not cheap.
It can be done though.
Is there anyway to fish a Cat-5 and use Balun's?
Then you could use Component or HDMI. A lot of companies make baluns. I've used the Gefen with great success.
About how much is "not cheap"?