Here's a picture of my folding bike, the Bike Friday Pocket Pilot. :) Out of my 4 bikes, it's my favorite. Why? Because it's so versatile. First, it was built to my body specifications, so it fits me like a glove. Second, it's lightweight and has great low gears to get me up just about any incline. Third, it can fold up to fit inside a car trunk, or you can disassemble it further, and pack it into its own travel suitcase, and check it as luggage on a plane, and fly anywhere with it, and there's no charge. :) I bought it 3 years ago, and soon afterwards started the DC Bike Friday club.
So, this will be the bike I will use when I ride to use a Zipcar - to fold it up and put it in the trunk of the car. I don't need a full-size car, a small car will do just fine. In fact, on the Zipcar website, when you are checking out the various available cars, it will tell you if the car is "fully bike-compatible" (i.e., you can fit the whole bike in, without taking your front wheel off), or if it's partially bike compatible. Either way, my Bike Friday can handle it. I have a nylon bag that I can put the bike into, and then put it in the car, so that no grease gets on the car anywhere, which is nice. :)
However, I haven't had to rent a Zipcar since Dec. 8. We had yucky weather last weekend, so I was inside most of the weekend, except my roommate did let me use her car to run to the grocery store to get some lunch items. And this weekend, I will be away in Kansas for Christmas.
In the meantime though, I have run a number of errands on my way to and from work. I have always enjoyed running errands on my bike - it always gives you a feeling of accomplishment, to get there on your own power, park right near the door, get what you need, and get home. Nice and easy...in and out. It doesn't cost anything to ride there, no parking hassles or cost, no traffic to fight, and you get exercise along the way. Actually, I sometimes find money on the road along the way - so you might say that I'M being paid to ride my bike. :) In fact, one year a while back, I was finding money on the road it seemed, almost every day. I wondered if I kept track for a year, how much money would I find?? So, I wrote down on my calendar every time I found money. At the end of the year, I added it up, and it came to over $13.00! Not bad! Nothing to retire on :) but still, it's extra money you didn't have. :) People in cars never see this money on the road - so I might as well pick it up and enjoy it! :)
So, I have run errands to several places. To the bank, grocery store, gift store, theatre, post office, and to meet a friend for dinner, to name a few. And although these locations are not far off the bike path I commute on, it does add a bit of time onto my commute...so I get home even later. But I figure I might as well take care of an errand here and there while I'm out there and on the way, vs. making a special trip all the way there on my bike, you know? It saves time in the long run.
One purchase I was considering (and may get in the future) is yet another Bike Friday, but this one is called the Tikit. (http://bikefriday.com/tikit) It folds even smaller than my Pocket Pilot, and has a bike cover attached in a pouch on the bike, so you can cover your bike and then roll it or pick it up and bring it WITH you, if you want to, like to a movie, theatre setting, museum, on a bus or commuter train. So it would come in handy if you didn't want to leave your bike locked up outside for long periods of time, and have it safe by your side or checked at a coat area. I am holding off to see how well I do with my other bikes before purchasing the Tikit. Even though I've admired the Tikit and what it can do, similar to the folding Brompton bike. There are some good advantages to owning one. But time will tell if I really need one.