'A new Cycle Hire scheme is due to be introduced to central London in summer 2010, similar to the successful Vélib scheme in Paris.'

'Key facts

Approximate numbers for the planned launch will include:

6,000 cycles
400 cycle stations
10,200 docking points (allowing approximately 1.7 per cycle should ensure users can return bicycles to the docking point of their choice)
An area of approximately 44km2

Whether you are a commuter, shopper, local resident, business traveller, leisure user or a visitor to London, the Cycle Hire scheme offers greater choice of transport as well as being an environmentally friendly and healthy way to travel. '

http://www.tfl.gov.uk/roadusers/cycling/11666.aspx