I saw my daughter using one of her empty mechanical pencils as a stylus on her DSI. I am sure it could be used on any electronic which has a touch screen.
Video game systems are expensive, but adding games to play with the system really breaks the budget. There really isn't a way to avoid the cost without avoiding video games completely, but there are ways to lighten the burden.
Tips and ideas for saving money on video games. Post your ideas here.