Last night I watched Donnie Darko on my Girlfriends PSP... and I was pleasantly surprised. Not by the film, which I've seen before (and highly, HIGHLY recommend) but by the overall quality of the film on such a twee console. The audio and visual quality was tremendous, even better than the quality on iPods and the like. It was a bit awkward to hold for an hour and a half and the battery was just dead by the time it was over but still. If I had one I'd certainly use it when travelling.
In other news, the film store on the PS3 gets a hearty thumbs up for it's ability to download the films direct to drive.