the Habitat for Humanity here welcomes used fixtures that are in usable condition. Have you tried goodwill or salvation army?

Craigslist or Kijiji in "free." I couldn't sell $600 worth of concrete curing blankets used one season for anything. Listed it for "free" and they were gone instantly

To donate to HfH or other resale charities, the items have to be in "gently used" condition. Anything that doesn't fit that bill won't be accepted. However, you can do a post on Craigslist under "Materials" and charge a nominal fee, or put them on Freecycle and they'll be gone before the day is out. Folks rehabbing rentals and other low income homes stay on the lookout for used materials. I personally have picked up several vintage lighting fixtures that way that were great items.

I've let HfH at a few places that were being demolished. The clients were pleased to get a nice charitable contribution receipt in most cases. I don't know if that's available in the US.

Thank you for the responses, everyone! I think I'll just try the free on Craigslist route. I looked into goodwill and salvation army, and neither one around here seems to take this category of donation. I think I'll be happy just to keep everything out of the landfill. :)

You might also join your local Freecycle and offer them up there. It is even easy to post pictures if you like.

I use Freecycle because it is local and the nearest Craiglist is in a city an hour or more away. Someone might even take them for reselling at a yard sale or something similar.

Once I get my lights changed out I intend to offer them up on Freecycle.

Here is a link that might be useful: Freecycle-Find a group near you

Look up "building materials - used" and you will find the local outfits. Many will bring a truck and haul away for free. I don't know if HforH's Restore does that, but they'll certainly take what you've got. In our area (DC/Northern VA) they take stuff way below "gently used". Good luck.

Freecycle. We've gotten rid of not only outdated stuff, but off-cuts of tile, old carpet, scrap wood, partial bags of thinset, you name it. One man's trash is another man's treasure.