I ordered a CycloDS Evolution for the Nintendo DS that I am getting for christmas. The cyclods seems to have tons of really cool features, and from all the reviews, is the best flashcart for playing homebrew games and backups. Unfortunately, getting them is somewhat difficult, as it seems the manufacturer is unable to keep up with the demand. My order placed over 2 weeks ago was backordered until Dec. 15 (today), but then upon checking mod-chip (the place I ordered from), the backorder date had been changed to Dec. 28.
I really hope I get it before or right after christmas. The whole reason I wanted a DS was for flashcart stuff (I want to make some homebrew software, play homebrew games, and yes… even roms).