I've included a few posts recently about coming up with a short pitch for your idea. In Paul Williams' excellent blog, Idea Sandbox, he suggests that the short narrations at the beginning of TV series are good models. He includes a few examples, including the opening of the classic series, "The A-Team":
THE A-TEAM (20 SECONDS)
In 1972 a crack commando unit was sent to prison by a military court for a crime they didn't commit.
These men promptly escaped from a maximum security stockade to the Los Angeles underground. Today, still wanted by the government, they survive as soldiers of fortune.
If you have a problem. If no one else can help. And if you can find them. Maybe you can hire...
The A-Team.
Sets up the basic idea extremely efficiently, doesn't it? Here's one more, from the current comedy series, "My Name is Earl":
MY NAME IS EARL (30 SECONDS)
You know the kinda guy who does nothing but bad things and then wonders why his life sucks?
Well, that was me. Every time something good happened to me something bad was always waiting around the corner.
Karma.
That's when I realized I had to change.
So I made a list of everything bad I've ever done and, one by one I'm gonna make up for all my mistakes.
I'm just trying to be a better person.
My name is Earl.
The visuals that go with this make it obvious it's a comedy; if I were using this as a verbal pitch, I'd specify first that it's a comedy and maybe give one or two examples of the kinds of funny wrongs that Earl is hoping to put right.
The next time you watch TV, pay attention to the short openings--Paul Williams is right, theyr'e a super source of pitching models.