Is there a ds emulator for iPod/iPhone that can play Pokemon
Yes you can but I think you will have to jailbreak your iPod Touch or iPhone. You can go to http://www.youtube.com/watch?v=7f7CAUiNSas and watch the video on how to get it.
No, even if you jailbreak there is no DS emulator
http://adf.ly/GNjmm download ds double sys here
http://www.youtube.com/watch?v=Cv_A-wdw1RsIt works fine & im using this right now on the ipad :)