Have you ever been in a position where you needed a quick break but your players were too ancy to break as well?
When dealing with nobility and court settings, players can sometimes skip the roleplay aspect and jump straight to behavior such as, "I bow, greet all in the court, and ask the duke for his assistance." While in most scenarios this type of action is sufficient, taking it a step further can enhance gameplay (or maybe even manipulate a plotline).
The spellbook of a long dead wizard that has gained the ability to read itself and cast spells from itself. If could be amazingly powerful as an ally, or use its magic to manipulate and rule a kingdom.