In response to Sleepingcities suggestion of olbas oil being a deterent, we heard that a used tea bag soaked in olbas oil would deter foxes from crapping in our garden. We dropped a couple in the most frequentled places and the next morning were disappointed to see that they had been ripped open by the foxes who were obviuously attracted to the smell! Aaaaaargh!

I've also heard that Jeyes fluid is good so we're going to try that next but I guess it will be a more unpleasant smell for us too. I heard that the best thing to stop a dog lifting it's leg on a tree or a lampost is to spray Jeyes.