The Tchibo shop in Surrey Quays shopping centre has a city style bike for sale for £120. I though it worth posting to the list as the topic comes up from time to time. Aluminium frame, with a front basket and strong rear rack. Kickstand. The most interesting feature is a rear seven-speed SRAM hub gear (ie. like an old Sturmey Archer but seven speeds). Front hub is a Shimano dynahub (generates current for the front and rear lights), so the bike always has lighting. The drawback from what I saw was rear suspension. The bike is not lightweight, but who cares for a city cruiser/shopping bike?
For the more weight concious, there are unicycles still in the shop for £45. But where do you put your bags of onions and french bread then?