It looks like Valve is up to something as Portal has been updated with the rather sinister update: "Changed radio transmission frequency to comply with federal and state spectrum management regulations"
Steam User Darth Tealc has managed to decode the in game audio samples from the newly added Portal radio that is scattered in each level, which when taken to the appropriate spot, an audio sample will play.
Radio achievement added and ringing the radios in-game to different spots in each map give soundclips SPOILERS:
I am decoding the images from the radio sounds - here they are - (EDIT: All have now been uploaded)
Note - dinosaurs 1, 5, 12, and 17 are morse code, not images. See this topic for the morse code translations.dinosaur2 - http://img685.imageshack.us/img685/2862/dino2.png
dinosaur3 - http://img169.imageshack.us/img169/5395/dino3.png
dinosaur4 - http://img40.imageshack.us/img40/8126/dino4.png
dinosaur6 - http://img199.imageshack.us/img199/474/dino6t.png
dinosaur7 - http://img186.imageshack.us/img186/804/dino7.png
dinosaur8 - http://img138.imageshack.us/img138/4015/dino8.png
dinosaur9 - http://img291.imageshack.us/img291/1900/dino9z.png
dinosaur10 - http://img502.imageshack.us/img502/6002/dino10.png
dinosaur11 - http://img62.imageshack.us/img62/5893/dino11.png
dinosaur13 - http://img442.imageshack.us/img442/2015/dino13.png
dinosaur14 - http://img99.imageshack.us/img99/6633/dino14.png
dinosaur15 - http://img203.imageshack.us/img203/2716/dino15.png
dinosaur16 - http://img51.imageshack.us/img51/3671/dino16.png
dinosaur18 - http://img4.imageshack.us/img4/5874/dino18.png
dinosaur19 - http://img222.imageshack.us/img222/8443/dino19.png
dinosaur20 - http://img13.imageshack.us/img13/8295/dino20.png
dinosaur21 - http://img13.imageshack.us/img13/6334/dino21.png
dinosaur22 - http://img10.imageshack.us/img10/6657/dino22.png
dinosaur23 - http://img85.imageshack.us/img85/4641/dino23.png
dinosaur24 - http://img222.imageshack.us/img222/1385/dino24.png
dinosaur25 - http://img168.imageshack.us/img168/4139/dino25.png
dinosaur26 - http://img148.imageshack.us/img148/3913/dino26.png