External TV tuner

I am looking for an external solution for a "TV tuner". I was looking at something from Viewsonic...

http://www.viewsonic.com/support/acc...onn4/index.htm

The only thing is that I am not sure if it would be compatible with the "new" signal that will be coming through cable soon. ( the signal will be all HD in our area soon)

I am kind of just poking around for solution. Any suggestions?

(long time no post)

If you're talking about over the air HD, that will require an additional converter. However I wouldn't worry too much about that-cable television is not held to those rules.