Those that use google as their search engine generally know that on special events or occasions, they switch up their logo to reflect the said image or event in tribute or celebration of it.
Why is this important? Well, about 2 days ago Google released a Pac-man themed version of their logo in celebration of the 30 years since the release of Pac-man back on the arcades. Little did some folks know that this particular logo was a fully working version of the Pac-man game, both as a single player version and 2 player version.
Generally, these kind of logo changes only last for the one day, but apparently it was popular enough that Google made it a permanent part of their site. You can try it here:

http://www.google.com/pacman/

Just make sure to insert that coin to begin playing.

So what other videogame references do you see in mainstream culture/society?

(PS: my best high score on this is currently 27770. Can you beat it?)