Tall oil is used for soap making, too. Tall oil products are considered more healthy and environmentally friendly than the typical tallow fatty acids commonly used in soap production, so people who follow organic, all-natural and even vegan lifestyles tend to use products made with tall oil instead of tallow.
I have read about tallow being used to make candles, too, so I can't help but wonder if maybe tall oil would somehow convert nicely into candles.
I guess not that many people in the United States use candles for practical means anymore so much as for religious reasons and emergency lights if the power goes out, but it's still an interesting thought.
If not for the fire hazard, using candles instead of your electric lights occasionally would probably be a good power saver, and using tall oil candles instead of tallow ones would probably give you even more brownie points as far as being environmentally aware goes.