I was talking to my friend and he was telling me about this
R4 DS card for the Nintendo DS. Apparently, he just downloads games and plays them using the R4. Reading up on it, it appears like you can download and watch video on your DS too. Listen to MP3 etc. I'm not sure if I understand it but apparently you can also download and play NES & SNES emulations too:
http://www.nintendo-ds-roms.com/
"R4 DS also know as R4 Revolution is a next generation Nintendo DS flash card. The R4 DS seems to be the most popular NDS card at this stage, the R4DS will totaly unlock your Nintendo DS console. Watch movies, store hundreds of games all on the R4 Revolution Nintendo DS flash card. The R4DS is just an amazing little device which is the same size as the original NDS cart, the R4DS is a complete solution with no need to purchase any additional components and is truly the easiest media enhancer out there. To simply put it, the R4DS is a must have peripheral for any regular Nintnedo DS or NDS lite owner. R4 DS is quite easily one of the best slot 1 Nintendo DS flash card on the market. ROM compatibility is virtually 100% on the R4 Revolution, just as long as you buy the right brand of memory. Otherwise, R4DS is 99.8%."
Above From:
http://www.modsupplier.com/catalog/r4-ds-p-208.html
Seems pretty awesome. Does anyone here know anything about this?