E-Build.com has some great eco-friendly products and tips on their site. Here's one of them:

High Efficiency Electric Panel Heater

ECO-heaters offer out-of-the-way wall mounting and is an economic way of providing efficient room heating at a low cost. Using convection technology, heat is mainly generated behind the heater in the space between the panel and the wall, which leads to an efficient up-draft of heat circulated into the room. This principle of convection means that about 90% of the heat comes from the back of the panel, while only 10% is radiated from the front of the panel. This form of "background" heating is not only very economic, but also safe and efficient. 

Your ECO-heater is designed as an alternative to conventional space heaters and other systems that use large amounts of electricity. It operates using the same electricity as 4-100 watt light bulbs, while heating an entire room.

There are numerous advantages to using ECO-heaters. They save on floor space, are safe to use around children and pets, and can be painted to match any décor with water based Latex paint. ECO-heaters are designed to be left on for long periods of time, giving you comfortable background heat at a low cost. This is similar in concept to a central heating system - yet far less expensive.

ECO-heaters are UL listed and International Safety Standards approved and have a 2 year warranty. ECO-Heaters are available at Gaiam.com for $158 .