Download.com is your friend Players:- http://www.download.com/3120-20_4-0.html?tg=dl-20&qt=3gp player&tag=srch Converters http://www.download.com/3120-20_4-0.html?tg=dl-20&qt=3gp converter&tag=srch Plus, there's a lot of software that comes with phones that play and convert 3gp files.
yeah, i'm talking about a video from a phone which records in that format but it didn't really come with any programs to work with it.
I think they'll play in Quicktime...I had somebody send me some .3GP videos once and all I remember is that one of the media players on my computer played them without downloading anything new. I know it wasn't Real or WMP, so that leaves either VLC (which I rarely use) or Quicktime.