I was just amazed to see that google had worked on such projects. Most of the people don’t even know about Google Patent Search.   Google has fully index and cross-reference over 7 million patents of past and present.

http://www.google.com/patents

For example you can search for who has patented Aeroplanes, mobile design or even a blouse

Computer Computer

Skateboard Skateboard

Monkey shaped camera bag Monkey shaped camera bag