This is my MP4 I've bought from dealextreme. Best $25 ever spent !!!
2GB, FM radio, AMV movies, internal speaker, 2" screen, 4 games included.
It works very well for the moment, apart from that there are some bugs while displaying ID3 tags (strange characters).
I don't know about the battery life.
I can't do anything with its firmware because it's a 9.xx version:
Maybe there is another solution to get all the files... ?
Currently I've got the FWIMAGE.FW but it's sort of fake, there is several bytes of data at the beginning of the file, but all the rest (about 6.1MB of 6.14MB) is filled with 0x0 bytes... S1res v4.00 isn't able to do anything on this file