The Velvet Society Blog has some nice close ups of the Poken hardware with some explainations of what looms inside the small contact creatures.

Poken hardware explained
Poken hardware explained 2

So, what is a Poken, really? I mean: how do they work?
Well, here are the two versions I know:

The left one is the Poken that was inside my Lift09 badge. It doesn’t look like a production model and the date on the edge says “02.02.2009″. The “cute” Pokens have a very different layout. If you [...]