Google launched a new Native Client Security Contest, where participants will have to discover security bugs in Google technology in order to compete to win cash prizes. Just complete the registration process, then download the latest build of Native Client, attack it to find security holes, and submit the ones you discover. You get credit for bugs that your team reports first. If another contestant submits a vulnerability before you, or Google publish a fix before you report it, well then... you'll have to keep looking!…contest will run until May 5th!
More info: Native Client Security Contest