LONDON -- With the heavy-lifting of game-week preparation out of the way, the San Francisco 49ers exchanged their helmets for their camera phones Friday afternoon.The team went sightseeing after Friday's practice as it moved to London for the weekend. The 49ers had been staying about 20 miles out of town.49ers coach Jim Harbaugh was excited about the upcoming expedition after practice Friday. A history buff and avid fan of Winston Churchill, Harbaugh said he was hoping to visit Churchill's war cabinet offices.