What are some fun activities that would be appealing to both adults and kids? We're thinking Tower of London and British Museum. I know Science Museum and Natural History are supposed to be good but we've been to these types of museums (in NYC) and wonder if the boys will be underwhelmed or bored. What goes on at Covent Gardens? Is Kensington Palace worth a visit? How about those on-and-off city bus tours? Any ideas appreciated. thanks!