I haven't had a chance to check this out yet but a quick search on ITT didn't pick anything up so I'm posting this for anyone to investigate that has more time than me right now :-)

It seems that YouTube has started serving some vids in MP4 format. Details.

Do these play on the tablets?

After my initial excitement of the BBC iPlayer serving MPG4 content that didn't play I'm not holding my breath but might be worth a try :-)

I watched part of the video, and it looks like they are encoded in h.264. I don't think there is a decoder for that, and even if there was I don't know if the Nokia has a fast enough processor to run them.

i've tried mp4 from youtube on NIT with mplayer-rc2.

The movie was too hi-res or too something else, mplayer had problems playing it