Cheap bi-wiring?

For very little money you can assemble a discreet bi-wire cable out of cat-5 cable available from Home Depot. Teflon insulated cat-5 is better, but the PVC insulated cable at Home Depot is good for less critical applications, and sounds better than stranded lamp cord style speaker wire. Even the stuff sold by Monster Cable and other companies. Cat-5 consists of 4 twisted pairs of wire. Each pair consists of a solid color insulated wire and a white color coded wire. The trick is to terminate the solid colors together and the non-solid colors together to form your plus/minus terminations. At the amplifier end join the plus terminations together and the minus terminations together from each cable. As Dan2112 mentions above there are forums on DIY cables that elaborate in much more detail and have designs that can compete with cables costing up to 1000$ a pair.

I have found bi-wiring makes an audible improvement with some speakers, and not others. B&W Matrix series, and Aerials, in my experience, sound noticeably more detailed and open sounding when bi-wired, especially the Aerials. I have a pair of Paradigm 60v2s in a second system and have found that bi-wiring the Paradigms provides no audible improvement even though there are provisions for bi-wiring and the manual recommends bi-wiring. Experiment with cheap wire before committing to an expensive bi-wire run. There is also the debate whether you should invest in one run of quality cable instead of two runs of a lesser quality cable for bi-wiring.