I took mine apart to resolder the headphone connector. It is a really really simple solder if you have any issues with the headphone connector cutting in and out.
I think the issue with mine was it was one of the earlier models though.
There are also some awesome open source games out there made just for the GP2X like Noiseza (or whatever it is called - very cool shoot-em-up with good music and artistic use of shapes - very Amiga-esque IMO). Easiest way to find them is Google for the bittorrent that they are distributed on.
