What's the point of all these commercial NDS roms all over the internet if they can't be played?

NDS Flash Cards.Dig on that.

ooooo, I remember seeing one of those for GBA.
I may get myself one, what's the best nds flash card out?

I'd recommend an EFA Flash Linker (www.efa.cc) with a PassMe 1 or 2 (www.dspassme.com/) ( <- Depending on your DS firmware, find out how to check HERE)

supercard, $40 and plays ds and most gba games

I could also suggest buying a big flashcard and get the cheapest passthrough device (Or WifiMe) and install the FlashMe firmware. With FlashMe, you only need the GBA cart. No more passthrough devices!

I use G6, but M3 has got a dumper tool.
It is from the same company though!