This isn't a great method, but it did work. I used my iPod touch (note: you will need wifi access on your iTouch or iPhone) and the WiFi Pad app to make an awkward but usable game controller. All you need to do is program the buttons under Options and get a server set up on your computer and away you go. it was pretty fun because of the general awesomeness of touch screens and the wireless part, but it was still pretty awkward to use.

I found a way of mapping the controllers, so now i snipe by pressing a, and then up/down on my + d-pad, just as efective as on clasic keyboard.

I really find this game more awesome now when I did this.