We had the creator of PunkSPIDER on our webshow yesteday.
Really great guy and he has made a very interesting tool that was shown at Smoocon 2013.
Basically it is like SHODAN, but it scans for vulnerabilities in websites for common issues, like XSS, Blind/ SQL Injection etc.
Its pretty powerful stuff - anyway, thought I'd share b/c I know you guys like this sort of thing!
http://www.concise-courses.com/infosec/20130502/PS If you have any questions on PunkSPIDER or PunkSCAN please post in the questions section on the page i just linked to and Ill contact the creator for a reply.
Enjoy.