In the NW USA, the place you buy oil is also the place you recycle the used stuff.
Waste oil heaters are one good use for it, but many up here have another use for small quantities (1 gallon or so). Used engine oil is an excellent chainsaw bar and chain lubricant (no need to buy new). It even comes in the right viscosity grades in the right seasons, 10w40 (or 20w50) in summer and 10w30 (or 5w30) in winter.
Some years back, I made my living with a chainsaw and used either used engine oil or the 'remanufactured' stuff. I liked the straight 30 weight 'remanufactured' oil during the hottest weather because the paraffin in it really makes it stick to the bar and chain. Both are good, cheap, never caused a problem and solved the problem of what to do with the used oil from my pickup.