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

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 an 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 your HDTV draws! ($24.99 from online stores, including www.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 must be at least 21 and have good driving records. (Starting at $50 at www.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. The fallback is regular alkaline batteries. Kit requires some assembly and is for experimenters age 12 and older, under adult supervision. The risk of Hindenburg-type flameups appears small. Making hydrogen is fun, but it's not something you'll do again and again. ($85 from www.Horizonfuelcell.com.)

DAHON CURVE D3

Bicycling is a great way to get around, but parking and storage can be difficult, particularly in cities. Folding bikes are one solution, and they aren't as weird as they sound. The Curve D3 folds up into a tight package, yet feels sturdy and comes with city-bike conveniences like wheel guards and a rack. It has three speeds, enough for city riding (unless that city is San Francisco). At 27 pounds, it's not something you'll carry around easily, but you'll have to pay a lot more for a lighter bike. It's a big seller at www.NYCeWheels.com, a New York store that specializes in folding and electric bikes. ($399.95.)

SOLIO HYBRID 1000

This solar charger for cell phones and MP3 players isn't a really environmental gift, since it doesn't save much power. Let's just say it's inspired by environmentally friendly technology. It's about the size of a TV remote, and could be useful for hikers or those with an off-grid cabin, but be aware that it takes a long time to charge up the internal battery using sunlight. The manufacturer says it takes 10 to 12 hours of direct sunlight (with no intervening glass) to charge it up. The internal battery can then fully charge a cell phone. If you have no sunlight, you can charge the internal battery via a PC's USB port. Any phone that can be charged via USB, plus Nokia phones, can connect to the Solio. ($79.95 from www.solio.com.)

THAMES & KOSMOS POWER HOUSE

This amazing kit lets you build a prototype home of one square foot and test several technologies for sustainable living, including solar heat, greenhouse gardening, air conditioning by evaporation, and desalination of sea water. Good gift for anyone ready to move up from LEGO, age 12 and up. ($140 and up at online stores.)