http://pajhome.org.uk/crypt/md5/
A javascript implementation of md5. Very handy.
http://www.win.tue.nl/hashclash/rogue-ca/
Fascinating paper on hacking SSL due to weaknesses in the md5 algorithm.
http://www.codinghorror.com/blog/archives/000953.html
An article on CodingHorror.com about how storing passwords as simple hashes can prove to be very insecure. Some recommendations are made including using a long salt value.