Sarif Industries, which appears to be nothing more than your average site for a cybernetic implant manufacturer (you know the type). After a few minutes of fooling around with the site, however, a hacking minigame begins, tasking users with avoiding security measures and retrieving data files.
The reward: Images and information about the cybernetic augmentations available in Deus Ex: Human Revolution. As marketing sites go, it's pretty nifty. If you're in the market for some new robotic limbs, check it out.