That way I could speedrun stuff on DS or Ps2.
It sucks being poor.
I can't afford any video games whatsoever. Indie horror games for the win.
Well... I'm not sure I'm allowed to suggest this here (I think discussion of emulators is allowed, and just LINKING to them isn't, please correct me if I'm wrong), but there exist emulators for both the DS and the PS2. That's what I use to record when I let's play games for the DS.
(The PS2 emulator, however, will PROBABLY not run at full speed. Just a warning.)