Give them to those who need them.
First of all, novice students in your gym or mountaineering school will be happy to use a bit heavier/older gear, but ease the burden of buying everything for their first trip. Just make sure that carabiners are safe, because the newbies can't tell themselves.
Then, any local non-commercial groups, who organize rope fun for kids or everybody. A hand-made fun park needs a lot of stuff.
Finally, if you are heading to a remote Asian mountain region this summer, you can take carabiners and old ropes, which the locals will happily use for many years in their households to tie their livestock, etc... Of course, this is tricky because of limited airplane weight.