I imagine this has been discussed before, but I honestly did search and nothing came up.
I recently purchased Evolution DS, a card that allows you to run Nintendo DS roms, and homebrew apps off of a microSD card on your Nintedo DS.
One homebrew app is a Nintendo emulator and it works beautifully. Seacrest out.
Link? I'm not familar with Evolution DS. Any modding required?
How well does it play on the DS?
Plays smooth as can be. Graphics slightly jagged (barely noticeable) which has to do with trying to fit the game on the top of the DS screen and I'm sure the resolutions don't match up.
http://www.cyclopsds.com/