How to pitch an idea for a TV show?

Let’s say I have a killer (IMO) idea for a TV series for a cable channel like Animal Planet; how does one go about pitching the idea? Do you send a summary of the concept, or do you actually have to film a pilot? Or is there something else that needs to be done?

Is this a docu-show? Film it yourself, hope to sell it.

Is this a scripted show? Get an agent.
It’s not a simple “I have an idea!” thing.

There is - or was - a conference that is set up for people who want to pitch their ideas for shows. Jay Leno used to film people there as part of his Pitch to America bits.

Let’s see, a quick bit of Googling reveals it to be a National Association of Television Program Executives (NATPE) convention.

The next conference seems to be the LATV Fest 2010. It will have a Pitch Pit.

Check out their sites for whatever information is relevant.