Didn't somebody say that Saturn's moons (some of them) might be covered in simple hydrocarbons? I forget where I saw the story, I think it was from one of the Cassini flybys or possibly the Huygens mission. Apologies to people who know about those missions, I'm probably mangling the mission details and misspelling the names.

If that were the case, we might expect life to evolve on a cold, hydrocarbon-rich world that does use the chemical energy stored in hydrocarbon molecules. If you can break down carbohydrates and get energy without ever involving free oxygen, can you do the same with butane? I think I saw a discussion in NatureNews about xenobiologists (love that word) looking into Formamide as a solvent rather than water. Formamide disolves nicely in water, but I think it's also good as disolving some nonpolar stuff like small hydrocarbons. Any physical chemists reading this?