Find a local CD/DVD shop that takes trade ins or buys used.

I think the OP means disks, not hardware.

First, make sure they do not contain any private data, and you have to err on the side of caution. If they do, and you have a shredder that does disks, shred them.

If not you might offer them on Freecycle or Craigslist (perhaps in the garden section?) - Some gardeners string them up to scare off birds. They make good coasters.

They can also be used for crafts, see if a local school wants them. I've seen really nice 'flowers' made with a cd as a base, with squashed/curled tea light aluminium bases used as leaves/petals.

There is a recycling center for these in Indianapolis, IN.
They take old VHS tapes, CDs/DVDs and cases for recycling. If you'd like their number, I can get it for you.