Challenge: Get your groceries without using your car
Grocery stores are (generally) in convenient locations so that shoppers can easily get to them to buy the stuff that keeps our bodies going each day. It's not always realistic to carry an entire week's worth of groceries on a bike, but the idea for this challenge is to try to get a week's worth of groceries without driving your car to the store.
You may choose to walk or bike to the store, but make a few different trips on a few different days in order to be able to carry everything with you. Maybe you take the bus, a taxi, or work out a carpool scenario with a friend who is planning to grocery shop (then the next week, you can offer to drive her to the store!). Whatever you do, leave your car keys at home!
Fun Fact: An average American spends 40 hours each year stuck in traffic. (Source: http://www.1800234ride.com/13-fun-facts-about-carpooling)