I was lucky enough to win a cone of Herdwick wool on e-bay, and it was delivered this morning; big cone of 31oz (879g approx), so plenty of scope there for experimenting as well as knitting. Interested to see how it fulls and weaves too. It's an aran weight in a lovely natural grey/brown. It's fairly rough to the touch, but would make great rain resistant hats I reckon so that might be one avenue to explore with it. I missd out on a cone a short time ago on e-bay but I suspect this is the same one, re-listed just waiting for me :)
http://www.nationaltrust.org.uk/things-to-see-and-do/page-2/view-page/item758527/268525/
Will report back when I've worked with it and see how it goes.