Over at coinopvideogames.com, they now have several pages of recordings that the host and his friend made in arcades with a portable cassette recorder. Not only do you get the arcade sounds themselves, but that impossible to replicate ambience of an early 80s arcade. One (read, me) might foll around and isolate the background noise and use it for a "live" track... would be classier than some boring old public domain crowd noise sample.
Remember the band 2Nu? Yeah, me neither; but I remember their novelty sound-collage hit "This Is Ponderous". If you were at least in third grade by the late 80s, see if this song doesn't ring a bell (not the real video).
This song was the only one of theirs to even reach marginal mainstream radio play. Want to get it high quality for free? Well, go to their website, where you can snag the whole dang album. If you decide you want to pay for it, they also have links to their iTunes page.
Utilizing an organ he purchased second-hand, David Byrne has created within the Battery Maritime Building (utilizing dozens of compressors, motors, and solenoids wired throughout the building) an interactive, site-specific musical performance installation/instrument, where the organ actually mechanically synthesizes old-building ambient sound by vibrating the girders, striking pipes and radiators, and blowing air through the plumbing. The project is calledPlaying The Building and it is currently open to the public until August 24, 2008.