"Okay, so?" or, "Stop staring at me and do something!"

[Ryo]

You could ask the players to detail the past of their characters a bit. Ask what goals the pcs have, etc. Then add that bit to an adventure. The players might get more involved if its personal.

[clockworkjoe]

BOX OF PAIN

[Joven]

I don't know, as a great sage once said "Pain don't hurt"

[crash2455]

Okay, I just ran into this last night with my Wushu game (Rock Band Zombie Apocalypse).  Before it started, I had clued them in to the Zombie Apocalypse scenario. 

Shortly into the game, I describe that rather clamming looking individuals are drunkly staggering into the show.  What do you do?

*silence*

You see more and more of them entering into the concert hall.  Upon closer inspection, you see that they've started eating the people at your concert.  What do you do?

*silence*

You get the feeling that after they're done, they might eat you.

"Hey guys, maybe we should leave."

Okay, they've piled on-stage.  You are surrounded by rancid-smelling drunks.  What will you do?

*Game finally starts to pick up*

Even after that, it wasn't until the second hour of the game that they really got into it.