I really like calling myself "Reverend" and have made up some business cards that have may "Reve." and "D.D." included - mainly to show off to people. I really don't use my Reverend too much though as the Government here is not really that big on the ULC or other "fringe" churches. However, if I am complaining about something, or do a "Letter to the Editor", I use my "Reverend" and "D.D."
At first, I never really thought of my credential as more than fun, but I am taking it more seriously now. I really enjoy being a Reverend.