Also for great prices on DVI and HDMI cables, check here
http://www.svideo.com
so far svideo seems to have the best prices I've been able to find on commonly std. length HDMI and DVI cables & adapters. They also offer free shipping and do not seem to gouge you for any of the more expedited shipping methods.
Example, HDMI cables: 3' = $8.95, 6' = $14.95, 10' = $16.95
They also offer every other type & length of cable imaginable.
One of the engineers at a local tv station gave me the tip.