[Pilot_51]

DS has 2 screens and a touch screen and microphone and wi-fi and full 3D, GBA doesn't. Many homebrew programs take full advantage of the hardware they're made for.
There's a drawing program called Colors (made by a professional game developer) that can actually sense how hard you're pressing on the screen; I bet you didn't know the DS could do that. Another popular program called Moonshell can sense the temperature; I bet you didn't know the DS could do that either.


R4, or R4DS, stands for Revolution for DS. The site you order from would ship it to you after you pay for it, otherwise you'd be getting ripped off. If you want to be safe, order from a site that you've researched and make sure they have a good reputation. Personally I think Sky2k has the cheapest prices with a trustable reputation, since I got mine from them incredibly cheap and couldn't find it anywhere else for cheaper.