1. BugMeNot
Bugmenot is simple. You enter the URL for the website you want temporary access to and Bugmenot returns a list of user-submitted user names and passwords. Each login has a percentage next to it that shows the probability of its success so you can easily see which logins have been shut down by the administrator. Even better, BugMeNot has a Firefox add-on that makes the process that much more seamless.
2. Anonymous Email Boxes
This service allows you to make a temporary address @makemetheking.com and check it instantly with no password or login. That's it! Just give the annoying website your dummy address and wait for the email to show up. Nice!