Things to do & see in London

http://www.timeout.com/london/sport/features/1706/London-s_secret_cycle_routes.html

i've done parts of these. if the weather is good then they are a great way to see the place

Ed is right, some of the best time is spent getting completely lost

A ride down the canal is quiet nice, you could always Putney/Hammersmith to Richmond along the Thames as there are a few pubs along the way ;p