Yes, you can use it to connect any WiFi capable device to the internet. This includes your DS, PSP, new generation Palm Pilots (like the T|X) and the Wii.
HOWEVER, it's a steaming pile of cow dung that only works sometimes and not others. When it works it works, when it doesn't work you'll want to tear your hair out.
Yes it's cheap, but you'll get what you pay for.