Moonpig is a saviour! I live two miles from the nearest stamp and three miles from the nearest Post Office, with an expensive taxi ride there and back. I can choose and create personalised cards from the comfort of home then press a button to send, marvellous!
I also send several Christmas cards to New Zealand. Knowing my order will be e-mailed down under first, then printed and sent out more locally from there, means I don't have to remember to do them in October to beat the international postal deadlines from the UK!