Although postcards are now virtually obsolete in daily life, I can remember a time when they were used to enter competitions, to cast votes in polls, and to let friends and family know you'd reached your holiday destination safely. But when I'm going away for a day or two, I like to maintain the last of those traditions. In most cases, I know I'll arrive back home before the mail does, even when it's within Great Britain, but it doesn't diminish the surprise for the recipient.