if you like the DVD ripper program, and are familiar with it.
the screen size is 320x240 the same as iPod video. select that size.
what i do, is lower the sound quality. lowers the size of the movie quite a bit. almost in half... think about it, you are watching a video on a small screen with for the most part 2 speakers (headphones or the like) you won't be able to tell the difference in sound quality.
up to you though.
the link above when you d/l it says it's corrupt.. Seabyrd Technologies - Blackberry Video Converter
found the site for it