When looking for fast .MP4 converters, I found one that is really fast and works great. It even transfers the videos to the PSP directly. It's called WinAvi MP4, it converts almost any video format to MP4(IPod, PSP, etc) and 3GP for other mobile devices. I've got to convert a 2 hours movie in 20 minutes, it was 1.3GB on size and it got reduced to ~600MB, less than half of the original file, with the same quality and video size. You have to pay for it, unless you look for a keygen or something like that. It's really great, I recommend it if you want to convert the videos. I think you can change the bitrate and get smaller files.