It's tough to be environmentally aware when shopping for holiday gifts.

For one thing, even products that proclaim their eco-friendliness are generally less friendly than giving nothing at all, when you think about how much energy it takes to produce and transport them.

Then, like most gifts, they end up in a landfill early next year.

There's another problem: Giving someone a carbon offset for their SUV is about as tactful as giving away a stick of deodorant. A lot of environmental gifts risk ending up as holier-than-thou recommendations for what the recipient should not do.

With that in mind, some suggestions for environmentally themed gifts:

• P3 Kill A Watt

It's strange how we buy electricity: We use our appliances without really knowing what they're costing us. All we get is a monthly bill, with no breakdown. Imagine getting a long-distance phone bill that doesn't tell you where you called or what each call cost. The Kill A Watt is a simple, inexpensive electricity monitor that helps you get a handle on your consumption.

First, plug the Kill A Watt into a wall outlet. Then, plug an appliance or lamp into the device. You can immediately read off the current consumption in watts or leave it on to let it count kilowatt-hours. Find out how much juice that new HDTV really draws! ($24.99 from online stores, including Amazon.com.)

• Zipcar Gift Card

A good gift for the carless, especially college students. Zipcar and the company it is acquiring, Flexcar, spread their rental cars out in garages in major cities and university towns. Customers get credit-card like cards that open cars they've booked online. Rates start at $5 an hour, making Zipcars practical for quick errands that aren't economical with standard rental vehicles.

For that extra environmentally friendly feeling, Zipcar has some Toyota Prius hybrids. A gift card can be used for the membership fee ($50 a year for occasional driving), or for driving costs. Drivers have to be at least 21 and have good driving records. (Starting at $50 at Zipcar.com.)

• Hydrocar

This toy car contains a fuel cell and runs on hydrogen gas, one of the contenders for the fuel of the future. It also demonstrates the conundrum of building a "hydrogen economy": The gas is a fuel but not an energy source. You have to make it first. The Hydrocar's fuel cell splits water into hydrogen and oxygen to create its own fuel. To power that reaction, the kit comes with a solar panel, but you need direct sunlight to make it work.