My brother's blog mentioned Java-Logs, these fireplace logs made from recycled coffee grounds. Brilliant! 

According to the manufacturer's website:

• Coffee has about 25% more energy than wood and triple the flame per unit of energy, so Java-Log provides the highest and brightest flames throughout the burn time.
• Reusing the waste from the world's most popular beverage reduces waste in landfills, and coffee emits about 14% less C02 emissions than wood when burnt.

If I still had a fireplace I would definitely be trying these out. It sounds very cool...or should I say hot?