Mark Waites of Mother saw an Argentinian Creative guy today, Tomas Quartino.

Like millions of Londoners, Tomas has an Oyster card. He also appears to have a very inquiring mind about how things work.

So his Oyster card is kind of unique.

If you look closely, you just might be able to see how it differs from a normal one?

And it's reported to work perfectly.

Brilliant.

An absolute pearler.

ps. If you still can't see how Tomas's Oyster card differs from an uncustomised version, this might help: