my gbaflash is probably the best investment in piracy that I've made... Actually aside from CDR's, it's probably the only one.
Anyway, there's a bunch of stuff for the GBA Flash cards that are pretty neat - pocketnes being only one of many.
Calcadvance, Coolpaint, Readboy, UFGBA Slideshow, Xdictionary...
I normally just copy a premade pocketnes rom each time, then fill the empty space with some other games. If the GBA games suck, I've still got pocketnes to waste some time before I need to make another transfer.