I saw them at Sur La Table in the US. I would imagine they might also have them in any kind of store that specializes in tying things up. I can take a look next time I'm back in San Francisco! (And I know just where to look...)
Here is a link I found!Travelberghttp://www.amazon.com/The-Food-Loop/dp/B000CDQE9Q
Yes, I have them, I use them, and they work great. Most often, I use then for trussing the legs of a roast chicken. They also work great for securing souffle collars. No end of uses, really.
Have you thought of these? http://www.lakeland.co.uk/product.aspx/whatsnew!11310