Penny Penates

«The first postcard ever sent, addressed to Theodore Hook Esq, of Fulham, London in 1840, was sent by Theodore Hook Esq of Fulham, London. The hand-drawn picture on the card caricatures the postal service and it is thought that Hook sent it to himself as a joke (there was no internet in those days, people had to make their own fun). Hook's card is also the only postcard known to exist which has sent using the extremely rare Penny Black stamp. The postcard was sold at auction in 2002 for a record-breaking £31,750 to postcard collector Eugene Gomberg.»

James Ward, Adventures in Stationery

(Read more about it in Wikipedia. Pictures also taken from Wikipedia website.)