Cheap touch screen PDA, cell phone, or otherwise?

I'm going to a convention in September and the character I am going as can not talk, so she carries around a black touch screen PDA. I need a PDA or cell phone that is touch screen and VERY cheap. I'm not looking to be able to call or text people so if you know something that would be of better use for me and CHEAPER than a cell phone or PDA please recommend it.