Thanks all for the replies - most days I try to feel nice and friendly towards the lost and the confused, but I suppose we all have days where we wish for a very long stick and a window at the front of the tower...
The problem we have is that there are only half a dozen private aircraft based here, so the vast majority are visitors who seem to have difficulty in finding the field, staying level and generally avoiding messy crashes - talking to them about the differences between various air traffic services usually results in the sort of look that says 'and you're telling me because...?'
Never mind - at least it's sunny today!
P.S. For all those that know me (or pretend not to) and for those that saw my heartfelt pleading for a job 8 months ago - despite the above whinging I am gainfully employed and very happy.