To those of you saying the high cost cables do *nothing*, there's a few falsities in that. For HDMI, there's a lot of benefit to Monster cables that most people are unaware of.
Sure, any HDMI cable can do 720p/1080i. Most inexpensive ones can do 1080p. Very few can do 1080p, 120hz refresh signals, 7.1 surround sound, and xv 12 bit color all at the same time. So the signal may be digital and all 1's and 0's, but it does still have bandwidth issues.
Also, I do believe Monster are the only cables to be UL certified, which is huge if you want to route it through a wall, because it's illegal to use anything not UL certified. That's really where they make their money. That and the lifetime guarantee that no matter what, they'll replace the cable.
Also, even though it's a digital signal, anything longer than 12 feet (roughly the longest the average person would use, so really not an issue to most) the signal degrades when not properly shielded. To prove this we opened up two 30 foot lengths of cables. One was a Monster, and one was a Nexxtech (roughly half the price). Put a ps3 on one end attached to an HDMI splitter with the sony made hdmi cable as a control. The two hdmi cords were attached to a tv in the two rear hdmi ports on a sony bravia xbr4 52 inch. The difference was night and day at that length. The Nexxtech really looked like a 720p/1080i signal, the Monster looked perfect.
Now commence the "I'm right and you're wrong" argument now, because I'm sure most of you are set in your beliefs about HDMIs.