Google announced on their adwords blog that they are expanding their pay-per-action Beta globally.
Advertisers who use adwords conversion tracking and receive more than 500 conversions in the most recent 30-day period will be invited to join the beta test, on a rolling basis..
You will be able to pay for completed actions that you define, ie; a completed sale. You can expect to pay more than you would for the regular adwords program so you better step up your ROI (return on investment) tracking.