Mike Lyle wrote:
[...]
Alternatively, if the wooden thing is too much bother, I find you
can
paint over that round hardish foam lagging they sell in the sheds.
A
cheap bouncy ball with a slit in it might make quite a neat cover
for
the tap itself, and should be cosy enough for most winters.

Good old Google! Have a look at this:

http://www.daxproducts.co.uk/tapcover.html

Should be available from Plumb Center, Plumber's World, etc; seems to
cost about £4.50.

Mike.