So, this is totally what you should have been doing a few weekends ago: The Urban Iditarod, through the treacherous and formidable streets of San Francisco. It's just you, a shopping cart, some willing friends to act as your "dog team" and pull the cart (mush! mush!), and your will to survive.
An estimated 1,000 people showed up this year. Sign up now for 2007. And no, it's not an April Fool's Joke (but could be).