One of the major benefits of CarSharing is that it saves money since owning a private vehicle, while very convenient, has many attached costs -- monthly payments, gasoline, oil changes, maintenance, parking, and insurance. Besides reducing costs, car sharing takes more cars off the road, reduces traffic congestion and pollution.
 
Or CarSharing is also great on the days you keep you car parked and take the bus or transit.

CarSharing is a pay-as-you-go car usage system.  Members go online, reserve a car and use their personal keyfob to access the car. Billing is both hourly and mileage fee based. Insurance, maintenance, and even gas are all included.   CarSharing has been shown to increase pedestrian, bike and transit trips by up to 54%.  Members can save up to $250-300/month.

CarSharing lets you choose to pay the costs of driving only when you want to drive. The Boulder-Denver metro area has a local non-profit carsharing organization called eGo CarShare.  Its over 2,700 members have access to a network of cars throughout the metro area, 24 hours-a-day, paying-per-trip, without commitment or inconvenience.

 

eGo CarShare: Denver/Boulder

Requirements: Valid driver's license of at least two years, decent driving record (usually five points or less)

Number of cars: As of May 2013, eGo CarShare has 42 vehicles

Car types: Many of the cars are eco-friendly hybrids or fuel-efficient, compact cars; eGo also has trucks (awesome for moving, even if you are a car owner) and a mini-van.

Rates: There is a one-time $25 fee to register. Monthly, and daily rates vary from $2.50 per hour with a $10 monthly membership fee, to $6.50 per hour with no monthly fee (and up to $75 a day) plus .$0.30 per mile. Rates include gas, insurance and maintenance.. Night owls and early birds: Cars are only $1 per hour from 11 p.m. to 6 a.m. 

Locations: About 20 locations in Boulder, and 15 Denver. View locations here.

Bonus: The nonprofit has a peer-to-peer sharing program for people who own fairly new, but rarely used vehicles. What does this mean? You can temporarily lend your reliable car to eGo CarShare. They'll pay for its insurance and gas expenses while its in their fleet, and give you a monthly stipend that you can use for any eGo car.