You probably could, but the iPad adaptor to play movies wouldn't work - you would have to find a different connection kit (or use an apple TV) to set things up. Since I have an iPad mini - it sits quite well into the cubby underneath the TV. I've got a 64gb iPad, so there's about 25 gb available for movie files. I sync what I want to watch to the iPad, and then plug the iPad in. The laptop might be too cumbersome to manipulate under / near the TV. I'm sure there's a number of ways it could be done. An apple tv is only $69 at best buy, and you could bluetooth stream movies over to it. I'm actually thinking about trying that option as well.
