Cycle Sportives

There's one for Stage 8 in London too. Gives you the chance to ride two laps of the circuit as part of a giant cycling festival, and all for a good cause :)

pretty neat, but at the risk of sounding uncharitable, it's a big fee (£50) for a little ride (20km), albeit in a good cause and on a splendid closed circuit

they seem to be discouraging speed merchants, however, so I reckon it might end up being an expensive version of Freewheel (or whatever they call that thing now), which takes place the next day strangely enough.