Aperture Science
If you haven’t checked out this fun ARG-like site for Valve’s Portal, it’s pretty funny. Aperture Science contains a questionnaire determining your suitability as a disposable test subject. The strong writing is probably the work of Erik Wolpaw of Old Man Murray fame, who’s at Valve now.
To get started, you’ll want to check out the first post of this thread.
Spoilers: (Don’t click the images until you’re done!) If the last screen doesn’t pop up for you, or you don’t want to finish all 50 questions, you can also skip to it by typing in “thecakeisalie”. Someone found this image in the flash file. Don’t bother writing down your user ID– just get rejected. Both ending screens are available here and here.

January 7th, 2007 at 10:09 pm
thecakeisalie
January 8th, 2007 at 7:31 pm
Er, you have to type “thecakeisalie” into the linked game, not into my blog comments.
February 20th, 2007 at 4:07 am
Hi. How do you get to the last screen, without typing thecakeisalie?
Don’t bother going to the website, unless you want to play the self-created game. I’m sure that sentence almost made sense.
My favorite question on the website is number 44. It says: Complete this sentence,
“The rest is blank”
Go Portal!
February 20th, 2007 at 4:13 am
I don’t actually know. Other people in the forums said they got to the last screen normally, by answering the questions and then “failing” the super-long numeric code at the end. When I failed it, it didn’t get to that screen. So I had to cheat.
November 6th, 2007 at 3:36 am
The footage almost looks like a videogame-
something animated. *Shrugs*
Did anyone notice the flash of something,
my mom saw it and said it was a cupcake.
February 26th, 2008 at 2:08 am
I took a screen shot of the flash and it is the cake that they show at the end of the game
April 1st, 2008 at 3:40 am
Actually, in response to that forum thread, the ADMIN username is CJOHNSON and the password is TIER3.
The thread is closed, though, so I cannot inform them. :c