An acquaintance of mine recently drove a group of his friends to a convention a couple of states away, probably 1,000 miles round-trip, under the typical 'I drive, you pay for gas' arrangement. It wasn't my place to explain to him that he'd been ripped off by his friends, big time.

Run the numbers. The vehicle they took got around 25 mpg, which means that the trip burned 40 gallons of amber gold. At $4 a gallon, the three passengers split a $160 gas bill, which figured out to $53 and change each. Edumund.com's handy "True Cost To Own" calculator for the Honda CR-V they drove shows that, based on 15,000 miles a year, over five years the cost per mile to operate this vehicle is $.52. This includes depreciation, insurance and maintenance, in addition to fuel.

At that estimate, the trip cost my friend $520. Minus the $160 in gas, he was out of pocket for $360, all for the privilege of chauffeuring his friends.

How can you deal with this situation? The easy way, or the hard way.

Every empty seat in every car clogging up the freeway in the morning is an opportunity lost: an opportunity for the driver to reduce the cost of his/her commute, for the traffic congestion to lessen, for the environment to breath a little easier. At present, we use only 15% of our car passenger carrying capacity in this country. If only there were a way for a driver and others sharing the same destination to match up....

This is the concept behind startup Avego. The internet site, currently recruiting beta testers, pairs up drivers with seats to spare with those willing to share the cost of the trip. Drivers use their iPhone and its GPS feature to register their location and destination. Avego attempts to hook them up via voice response, texting, or web interfaces with like-minded passengers. The passengers can use any cell phone; only the drivers need an iPhone.

Avego also calculates and apportions the passenger's share of the commute cost beforehand. Companies and other communities of users can create their own circles within Avego. The site also gathers feedback to identify and avoid inharmonious matches, and allows both driver and passenger to limit selections to those of his/her own sex.

Drivers in areas with high-occupancy vehicle lanes might find this service particularly useful in allowing them access to this time-saving turf. Avego, and the similar Pickup Pal, could really be useful if enough people embrace it. Critical mass is the key, and if this or a similar system were to click with the public, we could dramatically drop our energy use and pad our pocketbooks.

Register here if you're interested in being a beta tester.

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Pickup Pal: Thumbing a ride in the 21st Century

For those wishing to cut living expenses to the bone, transportation remains a huge hurdle. For thousands of years, hitchhiking has been a convenient answer.

However, in our paranoia-driven age, thumbing a ride isn't as easy or as safe as it once was. To overcome this hurdle, a new web service, Pickup Pal, uses the power of the internet and the templates of online dating services and eBay to match up driver and passenger.

Say I wanted a lift to New York City. I'd go on Pickup Pal and fill out a form, including a snapshot, origin and destination, desired time of departure and arrival, and a bid on what I would pay.