Borris's Bikes, outside the Imperial War Museum
A couple was actually seen riding two of them just before I took this photo.
For those not fortunate enough to live in the Capital, a word of explanation. The Mayor of London (and the council) have introduced a bicycle-hire scheme. In partnership with a major bank, whose name escpes me for the moment, they have introduced ranks of bikes like these which anyone may freely hire. Ir is all done with plastic, you pay with it. Take the bike and drive it to the rank nearest your destination and (providing that rank is not full) you park your bike there. Your card is charged appropriately.
I haven't used the scheme myself and don't feel I ever will. But that's just me! So the details on how the scheme works are approximate and not based on first-hand experience.
But I am sure it is jolly good fun,