DVD to PSP Converter
If you are planning on watching DVD quality movies on the go, a Sony PSP will be a better choice than a portable DVD player. Portable DVD players are not really that portable, since carrying a bunch of DVD discs with the equally bulky DVD player would be nigh uncomfortable. However, short of carrying all of your UMD movie discs along with you, you will need to do a little bit of extra preparation with a PSP before you can watch all of your movies on it. The most important part of this preparation involves using a DVD to PSP Converter.
A DVD to PSP converter is needed because PSPs will only play videos that are in the MP4 format, which is different from the MP4 format used by the apple iPod. There are homebrew PSP applications that can play existing movie formats such as MPG and AVI, but said formats tend to take up a lot of space out of the measly 1 to 8GB capacity given by Sony's Duo Memory stick. Not to mention movies formatted for the PSP will be more consistent in quality during playback, and will integrate well with the handheld's GUI.
A DVD to PSP converter is usually installed on a PC, where it can rip movies straight out of a DVD disc inserted in your PC's DVD drive, or converted a movie in your hard disc. Most of the converters available right now also has the capability to send the movies straight to your PSP using the PSP's usb connection or its WiFi network capabilities.