Guys who DIY their oil change, how do you dispose of the used engine oil? I feel guilty dumping it in the sewers.

I do it myself because I want every drop of the old oil out, so i normally do it at night and let the oil drain away the whole evening. To those who want to try this, just be careful not to forget you have no oil that night and keep that car in the innermost part of your garage just in case

Thanks

edit: I now have several used-oil gallons around the house, and the wifey's not very happy with it