Yesterday, Valve updated the PC version of Portal with a multi-layered unexpected surprise.
Layer 1: The first layer of this surprise is that every single test chamber has at least one radio somewhere. These radios are different to the original radios because they start off with a red light. If you grab a radio and take it to an invisible hotspot near by it will start picking up a mysterious transmission and the light will turn green. If you find all the radios and listen to all of the transmissions, you get an achievement. I’ve currently got 24 of 26 (EDIT: I ended up following a Youtube walkthrough. The ones I missed were a second one in the beginning of chamber 15 and the one in the hidey-hole near the five piston-pillars room in the escape sequence. I am mildly disappointed that there are none to be found in the GLaDOS chamber.).
There’s at least one in every test chamber, (EDIT: two in chamber 15), chamber 18 has three radios, and there are at least 4 (EDIT: 5) after you escape the test chambers (including the one in the fire pit).
Layer 2: A few of the messages are Morse Code (which spell out understandable but nonsensical phrases such as “LOL”), but the most interesting ones are actually Slow Scan TV images. These images contain numbers and letters and photos of objects.
Layer 2a: Several of the images are of objects found in Half Life 2 or Portal.
Layer 3: Putting the numbers and letters together in the proper order forms a md5 hash of a telephone number.
Layer 4: The telephone number is an old-school BBS which, if you connect to it properly, will send you back a bunch of ASCII text images and partially-scrambled messages that seem to be from Cave Johnson (the founder of Aperture Science). There is a mention of “GLaDOS version 3.11” which many believe to be a hint that there is going to be a major announcement on the 11th during GDC, possibly something about Portal 2 and/or HL2 Ep3.
There’s several very long discussions going on the in the Valve forums, and there’s already been a wiki set up. This is so fun!