I've always wanted someone to create a touch screen device that was the size of a pad of paper. I don't even care how much storage it has, although you can fit more into the form factor then something the size of a phone.

So if it had a touch screen the size of a pad of paper, had an iPhone(ish) interface, had some decent productivity apps, could play music and most importantly surf the web, I'd pay $1,000 to $1,500 for it.