Wow... the same price as normal DVDs that you can play anywhere? What a ripoff... cause you can only play them on a small handheld screen...
And why use the UMD movies, if you just have to recharge your PSP 3/4ths of the way through the movie? o.o
Just use your money to buy the DVD version and you'll be all set! x3

And yes, the DS can play movies and MP3s easilly!
For example:
http://www.lik-sang.com/info.php?cat...ducts_id=3983&
There are a couple of these kinds of things out there. And this allows you to do it a lot cheaper than the PSP ^_~
And Nintendo is even planning to release their own version of this product soon! =3