So I recently changed to D’Addario strings and seen on there website that they recycle old strings. Ya have to save up 2 pounds worth and they give you a shipping label even. I thought this was pretty cool. I didn’t want to throw them in the garbage and didn’t really know what I was gonna do with them.
(Recycle My Strings | D'Addario String Recycling Program)
Dave
Interesting, didn’t know this service existed. I’ll look into this and save them up although I suspect 2lbs weight of strings is a lot!
Edit. I’ve just weighed a set of strings (including the packaging) at 0.95oz. Assuming the actual strings are about 0.75oz, that comes to around 43 sets of strings.
I have 2 guitars and change strings maybe 3 times a year, so 6 sets per annum. So 7 or so years to collect enough strings!
On reflection, it’s the 43 sets of plastic packaging that’s the least environmentally friendly.
Yeah I thought that too… but iv’e just been throwing them in a box anyways so someday when I have that much I know theres a place to go with them. I live in a small town so there isn’t much for music stores. I would guess bigger stores probably take them too. It would be something to check into.
Dave
My local guitar shop has a string re-cycling bin. I save ‘em up and drop them off when I go in. I’ve never checked GC, but seems like a service they might have.
It’s only available in the USA Gordon, I came across it a while ago - they said it wasn’t worth it because of the postage costs.
@DarrellW
Next time I’m in a guitar shop I’ll ask if they recycle.
Note : targeted reply still not working for me ! 
Coincidentally, I just noticed a string recycling box at one of the local music stores, here. I’ve just been throwing mine away, but now that I know about the recycling box I’m planning on saving mine and dropping them off.
My wife collected my old strings for a few years and then made an art project of it. The strings were used to form a birds nest and she covered a few plastic easter eggs with a decoupage of musical notes. It was a gift to a fellow muso.
I saw this as well but I didn’t realise it was for the US only. I’ll have a look around to see if any of my local music stores do string recycling.
Just as an aside, Gillette do razor head recycling. Blade recycling
Wow, I honestly had no idea this was even a thing. Now I feel bad about changing out my strings and tossing them a few days ago. Thank you for the heads up!