"Here's a collection of NASA sounds from historic spaceflights and current missions. You can hear the roar of a space shuttle launch or Neil Armstrong's "One small step for (a) man, one giant leap for mankind" every time you get a phone call. Or, you can hear the memorable words "Houston, we've had a problem," every time you make an error on your computer. We have included both MP3 and M4R (iPhone) sound files to download.
That's just cool.
Now if only I had a phone that supported custom ringtones (yeah, yeah, I know... ) :/