"Short-term car sharing? It's a bit of a kooky idea, but the two companies - Zipcar and Flexcar - that have been making it their business since 2000 seem to be doing more than just idling in neutral.

Zipcar just announced it has reached profitability in its three markets - Boston, Washington, and New York. Flexcar plans to meet this target in early 2005. They've both come fairly far in the past few years: Zipcar, which started out with a dozen cars in Boston, now has a fleet of 400. Flexcar, which began in Seattle with four cars, has expanded to 350 cars and operates in five metropolitan areas. Both companies have ambitious expansion plans: while Flexcar hasn't given specifics, Zipcar hopes to tackle another 20 metropolitan areas. Are they filling a niche? "Our model offers convenience," Flexcar chief executive and president Lance Ayrault said. "Traditional car rental companies are filling a different need and are more cumbersome."

Zipcar is backed by $10 million in three rounds from Boston Community Capital, Gravestar, Seed Capital Partners, Evercel Inc. and individual investors. Flexcar plans to look at VC after it hits break-even."