Two new websites join the greenscape

— -- Two just-launched websites are promising to steer eco-conscious travelers down a greener path by including carbon-offset credits in the cost of a car rental and by scoring hotels on their sustainability.

Australia-born Vroom Vroom Vroom (vroomvroomvroom.com) not only offers car rentals with a lowest-rate guarantee through major companies such as Avis, Budget and Thrifty in more than 2,000 U.S. locations, but they will purchase carbon-offset credits, averaging $2 to $6 per rental depending on the size and mileage of the vehicle, for each booking.

WholeTravel.com, meanwhile, lets travelers search for destinations and lodgings using open-ended, descriptive keywords (i.e. "mountains" or "locally owned") and assigns hotels a "whole ranking" based on envirnomental practices, economic management, social and cultural support, and customer interaction. One snag: At this point, the hotels themselves supply the information, though Whole Travel plans to do its own follow-ups.