Disposal of old propane cannisters?

[Kelena]

I think they are still functional. There is surface rust, but that's it. They are the size that will fit under a BBQ, Aaron, whatever size that is (maybe 4 gallon as per ericlp above). They definetely do have a little propane left in them. Happy to drop them off -- email me if interested. Otherwise, I will try the recycle place. Mahalo everyone.