My whole house is wired for cable. Why aren't there networking products like they have for over phone lines that take advantage of the greater bandwidth potential of coax?

By the way, I am moving into a new office and I specified routing Cat 6 cable for Gigabit Ethernet. Now all I need are a couple of $80 networking cards and a Gigabit router of indeterminate cost. Gee. Now that I think about it I sure hope that the Cat 6 cable will work with Cat 5 connectors on my existing equipment. Hehe...guess thats why they made me an executive. I am just so decisive!