MD5 Online Calculator
A useful tool for computing the MD5 hash of a given string. You can input an ASCII string, a hexadecimal sequence and even a file! The output is also generated in hexadecimal and binary.
MD5 Reverse Index
The MD5 Reverse Index is a browsable listing of strings and their corresponding MD5 hashes. The pages are generated dinamically, so in theory it can be browsed ad infinitum.
Some random hashes: