When NPCs aren't simply being ignored by the players, they can come in handy for small pieces of subtle plot exposition. Place them in the roles of messengers and the PCs have to pay attention to them for at least a few seconds before brushing them aside.

Hey, that's better than most NPCs get.

Transcript

GM: Padmé, you're lying on a dune. A clone trooper approaches.
Padmé: Where did you come from?
Clone Trooper: Well, that's a complicated question, but according to my databanks, cloning pod number 1138 on Kamino.
Padmé: I meant just now.
Clone Trooper: Oh, right. Padawan Anakin pushed me out of the ship. I'm here to look after you.
Padmé: That was very thoughtful.
Clone Trooper: I wasn't wearing my jetpack.
Padmé: Right, we need another form of transport. I cast Summon Giant Sand Worm, like on Tatooine.
Clone Trooper: Um...
Padmé: When it gets here, you grab the dorsal—
GM: Let me cut this short for once. Giant worms in a desert is just silly.
Yoda: The giant sand birds would eat them!
Padmé: Bummer. How will we get to the fight?
Clone Trooper: It's a day's walk across a scorching desert. And you've been eight hours in the arena without any water.
Padmé: We better run!