I have a few 3gp files from a Nokia phone my rents back in the UK sent me, anyone know how to batch convert them to MPEG-1 video/audio profile (suitable for playback on a dvd player?)

http://www.miksoft.net/mobile3GPconverter.htm

this can convert a 3gp video to a raw avi, which you can then encode however you want (such as with nero vision express).

I also found this, but Ive never used it before so dont know if its any good.

I have used this a few times http://www.effectmatrix.com/total-video-converter/index.htm
not to bad.