Owning a car in San Francisco is a terrible bargain. Beyond the expense of buying the vehicle and paying insurance, traffic and parking are such deterrents that many car owners drive only often enough to avoid street-cleaning tickets. City CarShare premiered last year as an alternative, offering shared new VWs (mostly Beetles) on a per-use basis. Sure, it sounds a little steep -- a $25 sign-up fee, $300 deposit, $10-a-month membership, plus $2.50 an hour ($25 a day maximum) and 45 cents a mile (a gas card is included). But it's still a whole lot cheaper than owning a car if you're not a frequent driver. Once you've become a member, you simply reserve your time online and then pick up a car at one of the 13 parking lots around town. No longer do you need to feel guilty about driving to IKEA for a new bookshelf or Trader Joe's on a pantry-filling mission. City CarShare may not be taking drivers off the road, but it's certainly reducing the number of cars. That's something even other drivers can appreciate.