Ambient Backgrounds

Like most coders, I'll put on a YouTube mix, or let Pandora shuffle about in the background while working.  But once in a while it's just nice to just have some ambient background noise.

Sure, you could have a fan blowing around, but what about the background noise of the TARDIS?  Or the idling engines of the Enterprise?  There's a ton of these up on YouTube, often lasting hours at a time.

Here's a sampling: