It's not too late to start knitting a cushion for Woolsack. There are stuffing events at Woolfest in Cumbria the weekend after next and at Fibre East in Bedford on 14th and 15th July to which you can bring your cushion plus yarn and needle for finishing to be stuffed with pure British wool.
I've just knitted the swatch for my cushion. It's going to be knitted from pure Shetland yarn from Black Yarns with honeycomb and simple braided cables. If you're travelling to either Woolfest or Fibre East then a Woolsack cushion would make the perfect in-car project.
Never heard of Woolsack? Read all about it
http://woolsack.org/. It's a fascinating project undertaken by British knitters with the aim of giving a handmade cushion, made from British wool, to every Olympian and Paralympian who wants one. They're leaping over the hurdles presented by the stringent LOCOG restrictions and now are sprinting towards the finish line thanks to recent publicity on BBC Radio 4, BBC Breakfast Television, Look North, and in Private Eye.
If you'd like to make a cushion for an Olympic or Paralympic athlete the main things to remember are that it must be made from 100% British Wool, be 16"x16", and not feature any of LOCOG's list of restricted expressions or marks - the full details are here.