Visitors to London for next month's royal wedding will be able to get their hands on a limited-edition Oyster Card, it was revealed March 29.

The Mayor of London officially unveiled the new design for London's public transport pass, which will go on sale in the week leading up to the April 29 ceremony for Londoners and visitors alike.

A total of 750,000 will be produced and sold from London Underground and Overground stations, requiring a £5 (€5.67) deposit and a minimum £5 top-up - although they can also be used to pay for all buses and tube journeys in the city.

London produced a similar paper ticket back in 1981 for the wedding of William's parents, Charles and Diana, and believes the new high-tech smart card could become a collector's item.

Visit London predicts that an additional 600,000 people will converge on the British capital for the royal wedding, lining the the royal procession route along The Mall, Horse Guards Parade, Whitehall and Parliament Square.

That's a lot of competition for the Royal Oyster cards, although perhaps not as much as there was for the 35,000 commemorative SmarTrip subway cards produced by Washington for the 4 million visitors that attended the inauguration of Barack Obama in 2008.