trackpad on the back of the neo

[Robin Paulson]

sorry for the slashdot re-posting, but this would be great on the neo
- and i'm sure someone here suggested it a few months back

http://www.xconomy.com/boston/2009/04/10/at-chi-meeting-microsoft-turns-computing-interfaces-on-their-head-and-side-and-back/

i think the idea of using an image of the finger is extremely naff -
turning on a decent-sized cursor would be far better

it looks pretty simple to realise - can anyone recommend a source for
a very slim touchpad?