I just discovered the BugMeNot service today.
It offers a database of logins shared by the community to login to free websites that require free registration.
This is usually annoying to subscribe to such a website just to download a freeware or read an article, and it often makes people choose unsecured or random logins.
They even provide an extension for Firefox. Thanks to this great website, you are probably going to save a lot of time.