To figure out the password, you're going to have to search all over the forums for puzzles. Unlike past puzzle contests, the order in which you find them is completely irrelevant; they are independent of each other, and they all give one piece of information to help you unearth the password.
Each puzzle, when solved, will yield the name of a color. Once you've figured out the color, you get to relive your childhood and do a little bit of coloring-by-number!
I'm going to help you out a little bit and give you the first color: red. Now you can fill in your first picture:

(yes, this is actually one... this is unprecedented easiness in a forum game.
Save all your completed pictures! You'll need them to decipher the password.
When you get into the secret forum, make a post in the Winners' Circle thread for posterity.
As always, working in teams, deliberately deceiving others, and utilizing search engines are all valid tactics.. make sure you know who to trust!
So feel free to go ahead and find those puzzles hidden all over the forums.... just make sure you don't get your hands sticky from all the glue, post-it notes, and tape you'll be encountering in the process. It makes the "enter password" button quite grimy.
PS: Once you have all the pictures, you may want to pull up a chair by the pool and think about what they could mean.

