...what to do with this leftover, scummy paint?

Apparently just throwing it out is not a good idea. If you have good paint, save it or give it away. Don't be a douche and "dry it out" or use kitty litter, because that litter could be put to cat use AND YOU WILL PROBABLY NEED THAT PAINT. Touch ups. New projects. That time you tried to move a couch into your apartment and it juuuuuuust fit.

Anyhow, my paint is super old and has flakes in it, so you have to look up your town and paint disposal, then just bring it in. For Chicago:

City of Chicago:	1150 N. North Branch on Goose Island Tue:  7 am - Noon Thu:  2 pm - 7 pmFirst Saturday of every month:  8 am - 3 pm
	Visit the City's web site at www.cityofchicago.org. Phone:  311 or for general info:  312-744-7672