I began searching online (including Re-Nest, of course) and found The Carpet America Recovery Effort. In my local area, to drop off a pickup truck full of carpet and padding at The Carpet Recyclers, the fee is only $25. I'm totally willing to pay that for the 320 square feet of carpet and padding to ensure it's diverted from the landfill! The rules are that it can't be carpet scraps, must be clean (no caked-on dirt, adhesives or construction debris) and the carpet padding must be re-bond padding (the kind that is a collage of colors pressed together into foam padding). Currently, many recyclers don't accept carpet tiles, but be sure to check with your local facility to make sure.
I can't justify replacing the carpet the bedrooms yet since it hasn't yet seen the kind of hard use the garage apartment did, but I'm thankful to know that it will eventually be turned into something else very useful.
(Image: Shutterstock/Huguette Roe)