Google is mounting a multi-facted campaign to get people to register to vote and actually show up at the polls. There’s a voter information/registration map and a mobile version. There’s also a widget/gadget you can embed in your blog or site. It provides registration information, tied to home address.
Google is also helping promote a celebrity effort to get people to vote with a novel “don’t vote” message:
Meanwhile, the Obama campaign has released an iPhone app.