A topic of frequent discussion on BBI, figured I'd link it if anyone was interested. The Slingbox lets you place shift, using a browser or mobile device (additional app fees apply) to watch your TV on the go.
http://astore.amazon.com/bigblueintera-20/detail/B009FU8BTI - (
New Window )
if you are streaming HD channels you probably don't want to be hooked up via wifi. I understand where you're coming from as your modem has to be where your cable box is.
I have a slingbox pro I got on ebay for $40. really cool toy. I'm trying to get my cousin to get one in the albany area so I can watch giants games.