But before the official announcement, clues of Portal 2's existence were embedded in a patch to Portal that Valve released a while back. What do I mean "embedded"? Well, the patch added a new episode of the game where you had to take an in-game radio to various in-game locations, and you would hear weird sounds. Some words were intelligible, but mostly is sounds like like noise.
- Some of the sounds were morse code which, when decoded, looked like messages from a computer restarting. (The premise of Portal was that you had to defeat an evil computer gone haywire - hence, sequel)
- One of the morse code messages was 9459C6CAC8C2Q3B8T28B7CC6306894FD, which is the md5 of "the quick brown fox jumps over the lazy dog"
- Another of the morse code messages, when decoded, spelled out "beep beeeep beep beep beeeep beeeep beeeep beep beeeep beep beep", which, *when you interpret it as morse code* spells "LOL"
- If you converted the sounds to *images* (using SSTV, a standard for doing that. No, really.) you got hidden screenshots of (presumably) portal 2.
- One of the pictures included clues which led to another MD5 string, which could be reverse-hashed to a BBS phone number which, if you dialed in, you would get Portal-related ASCII art. I'm not kidding.
Apart from being possibly the coolest and geekiest patch for a game ever, it's amazing that fans of the game who downloaded and played the patch actually *found* this stuff without help from Valve. Anyway, I guess there's some in-game or real-world achievement at the end of it all. I don't know whether anyone has found it yet, though.