Dual cable modem and tv tuner card?

Hey everyone,

I was just wondering if anyone's heard of a dual cable modem / tv tuner card? Has anyone heard of these, do they exist, or know where to find one?

The way I figure, tv tuner cards just have a lil input for a tv cable line, so why not have it built-into a cable modem?

Also ... if they do exist, would they work with Optimum Online?