Google Alternatives: Smart Search Engines

Here is a list of great alternatives to Google for searching online.  I will do my best to add annotations to the links soon:

Technorati (a blog search engine)

http://www.technorati.com/

ChaCha

http://www.chacha.com/

Rollyo: Roll Your Own Search Engine

http://www.rollyo.com/

Kosmix

http://www.kosmix.com/

Ask.com

http://www.ask.com/

Clusty: the Clustering Search Engine

http://clusty.com/