JPassGen is a simple password generator to protect your accounts, applications and files that may be vulnerable to unauthorized access.
It generates keys of any length, and you can specify what kind of characters to include i.e. letters, numbers and symbols. You can also set it to remember your passwords so that you don't have to keep entering it to access your files. The author of JPassGen recommends you use at least 10 key characters, including letters, numbers and symbols, although you have to be careful. Uppercase & Lowercase letters, numerals & special characters can be used in combination to generate strong passwords whilst user specified characters or symbols can also be used. Note that you'll need Java's Runtime Environment for it to run properly which is a bit annoying because it's rather heavier on resources than it needs to be.
A useful tool for anyone that uses passwords over multiple applications and is worried about security.