If you get books in the mail on a regular basis, you, like me, might have a build-up of used padded envelopes. I will not throw them away...but what to do with them (I get more books then I send, and they build up fast)
At last, I have an answer--my local public library system wants them very, very badly indeed! They use them to send interlibrary loans of dvds and cds. I happened to be hanging out in the library the other night (as is my wont), watching the librarian making do with scraps of very old packing material....this evening, I brought her a whole armful of the envelopes, and she was thrilled!
So do check your local library! If they aren't needed there, save them up until you have a few box fulls, and offer them on Craig's List or Freecycle. This is what I've been doing until now.
(My next gift to the library is going to be organic apple twigs, to be offered as gifts to those attending the Care and Keeping of Your Rabbit talk).