Bobblehead - Strength is a Fallout 3 item, a Vault Boy bobblehead. It permanently improves your character's Strength by 1, to a maximum of 10.
The bobblehead is found in Lucas Simms' house in Megaton, on a desk in the bedroom (door to immediate left at top of stairs) on the second floor.
If Megaton is destroyed during the The Power of the Atom, this item will be unobtainable.
The bobblehead in Simms' house