A lad from another forum I met had a pretty good idea - he registered on a business card website and designed himself a business card. As with most websites selling business cards, they send you a free sample pack of 250 cards if you cover the postage costs.
I personally thought it was a good idea and looked quite professional when accompanied by a letter and copy of insurance details.
I'm yet to apply for any permissions, but when the time comes I think I'll try the business cards.