I just released a wee piece of software, called RA-WebPass which is simply a webpage that you can use to change linux system passwords.
Basically, I wrote it today out of my frustration with customers asking me "how can I change the password for the FTP server". Ok, this is how you can.
It's simple and doesn't have too many dependencies, so it should be rather secure, but don't trust me on that, and you need to run it as root, so be very very careful.
On a related note: it's quite satisfying to write something in two hours and just release it :-)