I should add to Jackie's note that certain vehicles are excempt - so lets all go out and buy a minibus and really scupper Ken's day!
For more information on the congestion charging (one zone only - you are either in or out!) see
www.cc.gov.uk!
As for living inside the zone it is just another form of road tax but with this one at least I get a 90% discount, so have paid att £126 for a whole year. don't like it though cos I also pay my road tax, car tax, insurance and VAT etc as well.