Whenever anyone you know has doubts about spending public money on stuff like NASA or the Curiosity landing that went off without a hitch last week, direct them towards the site WTF NASA [Warning: NSFW language].
The site is loaded with answers to the simple question, "What the f*** has NASA done to make your life awesome?"
When you load up the site, you are given example after surprising example of how NASA has changed our lives for the better. Some examples the site spat at me: 'Invisible' braces — the material used in these braces was created to protect the infared antennae of heat-seeking missile trackers"; Weather forecasting — NASA's GOES satellites provide most of the weather coverage for most of the Western Hemisphere; UV coated sunglasses — coating was created by teh Jet Propulsion Laboratory to protect astronauts eyes from radiation.
To see more, go to the site. To advance to the next fact, click "That rockets!"