I live in the USA - do you have anything there like craigslist.org where you can list things that you want to give away for free? Or could you put it on eBay for just a few cents and tell them they have to pick it up? Or does your local newspaper have a section in their Classified Section where you can give stuff away? Or maybe check with a local charity or church to see if they know what to do with it. Hope one of these helps Steve.
I agree with tonyted freecycle.org is great for those things that you don't think anyone would buy but are too good to throw, and gives a great sense of satisfaction.
your old carpet would make a good grond cover membrain,it would stop the weeds growing but also let the groud breath,this could be used under bark,gravel.etc..if you cant use it ,im sure their is somone not far away who could,its a very low maintainance popular option...