Get a decent pda instead. Huge community, constantly updated, loads of stuff.
The emulation of most of the systems are not very good on gp32, unless you prefer slow motion... though it's a second best choice to a pda if you are willing to do some programming on your own. If not, just stick with an ipaq or something.
Actually cartridge sizes on a pda or gp32 are in megabytes, while on gba it is megabits as is traditional in console world...