These are two services I know of that use it for cool stuff with user permission: * Authentication: http://www.copsonic.com/ http://www.copsonic.com/ * Shoppi

These are two services I know of that use it for cool stuff with user permission: * Authentication: http://www.copsonic.com/ http://www.copsonic.com/ * Shopping deals: http://www.shopkick.com/ http://www.shopkick.com/