3gpp2 is the nicest looking format for phones ive found. and if your looking for a converter that will convert any avi, mpeg, ect. i use freez 3gp video converter and it works great. i dont know about your phone but on mine i have to have the videos in the right folder on the minisd card and i can only watch them in a certain spot in the phones menus, it may take some playing with to get it right......
good luck i though it was a piece of cake but im a MCSA and have worked with computers for about 10 years corporate and home....