Loony you forgot to mention a slot-2 flash cart they could get. OP, if you really want to play GBA ROMs on your DS, get an EZ-Flash 3in1. It's $20, but it's a good deal considering you'll be able to play ALL GBA games with it.
Actually, there IS one now. http://gbatemp.net/t281715-gba-emulator-for-ds-i enjoy 2 fps on GBA homebrew totally beats getting a DSTWO or PSP, or just a GBA cart. also, even though the link says gba-emulator-for-ds-i it works on DS-mode too.
indeed it does. With dsi mode you get 4 fps and commercial rom support. nevertheless, this is still a GBA emulator that runs on the R4, dsimode or not.
Cool, did not know. Point still standing, the guy who made the Yu-Gi-OWNED wii exploit made a GBA emulator that runs (albeit slowly) on DS and DSi in DS and DSi mode.