What do you do with those styrofoam packing peanuts?

[Delphinus]

Ok, so everytime I MO something, it comes in a box filled with packing peanuts. Which I dutifully don't throw out because that would be "bad." So I put them in a garbage bag full of them "just in case I ever have to ship something somewhere." Now I have .. well .. a few of these bags just chockablock full of packing peanuts and.. it's starting to get kinda annoying.

What can people do to get rid of them in an ecologically sound manner? I was seriously thinking of asking a place like Mailboxes Etc. if they want them, but just haven't done so yet.

I'm thinking that realistically I'm looking at that I have to make a 3-Glad-bag donation of styrofoam packing peanuts to the landfill, but just thought I'd ask what others do...