Online MD5-Decription service

[rasenove]

It works by, inputing a MD5
hash and it search for its decrypted state in their database, witchcontains over 15,186,868 unique MD5 hashes

www.md5decrypter.com/

[DaNePaLI]

Bigger Databases:

http://www.md5decrypter.co.uk/
http://www.tmto.org/pages/passwordtools/hashcracker/
http://crackstation.net/

Actually, the third site consists of several good articles. You guys might be interested in reading them. I do recommend reading those articles.