I watch video on my little devices all the time. Heck, I used to watch on my iPod Video and sometimes even on my 1.8" Sansa! (When I was really bored on a train usually.)
But I noticed something interesting this weekend. My 6 year-old was watching something totally intolerable on our main TV, so I sat on the couch with her and watched a Led Zeppelin documentary on my phone. I was amused to discover that at comfortable viewing distance, the phone covered the same field of view as my big TV did across the room, so I could hold it up and exactly cover the screen...or pretend we had dual large screen monitors. It was fun. Really, it was.