This is the electronics for the Forepaw, my North Paw clone. It consists of a compass module, an Arduino microcontroller, a shift register, and eight vibration motors (such as you would find in a mobile phone). And a battery connector, battery case, some veroboard, some ribbon cable and some bell wire. You may just be able to see that the fifth vibration motor from the end of the ribbon cable is vibrating.
You can find the source code and some construction notes on Gitorious . A big thank you to Eric Boyd from Sensebridge who gave me some insight into the construction of the original North Paw when we met at the Quantified Self conference.