It's been a long time since I've played Portal, but this Olympic Stadium rig sort of looks like GLaDOS from Portal.
Kotaku tipster Ian summed it up: "Anyone noticed the speakers hanging from the athletics stadium at the Olympics kinda look like GLaDOS?" No, but now that you mention it...
Apparently, this isn't a speaker but some sort of lighting setup — but I'm not positive. Then again, it also might be Aperture Science's latest genetic lifeform and disk operating system, out to kill and make us all feel very, very guilty.
Olympic Stadium GLaDOS [DeviantArt — Thanks Ian!]