Spider maps are now appearing at London bus stops at important locations. They show all bus routes from the location in the style of the schematic tube map, with all stops listed withing a certain radius.
The central part reverts to a normal street map of the location showing all bus stops. There is also a key showing which bus goes from which stop (useful when there are many like at Trafalgar Square), and the destinations of the buses (and night buses).
Spider maps are extremely useful to see at-a-glance which bus routes go where you need to go. In combination with the all-London bus maps and the timetables, bus information in London is extremely good.