NASA offers a terrific collection of free MP3 sound files and M4R ringtones, from astronaut quips and greetings to the explosive liftoff of rockets to Sputnik's pulsing beep.
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.
