Our TV at home has internet capability (as well as our blueray player, Tivo, & Wii)... at home we use those to connect to Netflix or YouTube to watch video.
While camping we can (though normally don't) watch videos over cell by connecting my cell phone (Motorola Atrix) to the TV via HDMI. This is not practical for watching too much video, but for an hour or two a couple times a month it works with our data plan.
Our cable service (ComCast) also has an Android app which allows us to watch some video through our phones... not too much is available though. If you subscribe to movie channels, there are more video selections available.
Happy Camping!
John.