According to Alan Smithee :
I've been ripping out a lot of old plumbing in the last little while and now
I've got a couple of dozen elbows with various lengths of pipe in them. What
should I do with this stuff? I've thought of trying to reclaim the elbows by
sweating the pieces apart but it seems like a lot of work. I can't bear the
thought of sending it to the landfill. And I don't know if it would pay for
the gas required to drive it to a scrapyard either, but maybe that's the way
to go. Any ideas or projects that use old copper plumbing? Thx.

Sculpture, especially water fountains ;-)

[Our house was custom built by a plumber for himself. He obviously had
lots of extra bits and pieces, the antenna mast and all the closet rods
are copper pipe. So far our closet renovations have practically paid
for themselves in liberated copper pipe ;-)]

Scrapyards may pay as much as a buck a pound or so for copper. Some
"architectural scrap dealers" may pay more for useable fittings.

I've liberated modest amounts of more normal sized copper, and that gets
pulled apart, and slowly gets reused in new projects.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.