Clif Bar is sponsoring a nice little promotion called the 2 Mile Challenge. The idea is simple: maybe you can't ride the 14 miles to work each way, but you can certainly ride the 1.5 miles to your friends house, or the half a mile to the grocery store or 8 blocks to the library, etc...They have a nice little film on youtube that promotes the advantages of biking over driving. Trimmed to 30 seconds it could make a nice PSA.
Though I'm pro-bike I try not to be anti-car. The car has it's place in the full transportation spectrum. I just think it's overused (and over-subsidized). I ride my bike almost everywhere - even when it's not faster or cheaper, but I realize not everyone is going to do this. If one could show people those times when bikes are advantageous from a time or money perspective I think that could significantly reduce car trips (and with it congestion, pollution, obesity, etc...)
I think a lot of people are unaware that the bicycle is the ideal transportation method over short to mid distances. I would never want to force people to ride their bikes, but I think if they give it a shot they'll find it's faster, cheaper (especially if you have to pay for parking) and more fun than driving. That's what the two mile challenge is all about.
I've taken several newbies on the 1 mile ride from my house to the Mall or the baseball stadium. Some have complained before hand but they were always converts by the end, it doesn't hurt that when we come home afterward we're already on beer #2 by the time those who rode the Metro home walk in.