I know that your meant to sum up your whole submission in a couple of sentences, but this seems very hard to do whilst at the same time being funny. Does anyone have any suggestions, or things they do, that may help?
How do you write a tagline?
Look IMDB for examples, try your favourite comedy shows or films.
Write a description of your show and keep cutting out words you don't need.
"Write a description, cut out the crap."
Is it meant to be funny? Or just make the reader really interested in reading a script?
If yours sitcom has a dominant lead character(s) you could base a tagline on the defining characteristic or relationship.
Baby Cow seem to like doing this, e.g. Gavin & Stacey 'if only it was just the two of them...' or Saxondale being 'still the cleverest and dumbest guy in the room'.
I'm just finishing a new sitcom about a fairly obnoxious sales rep., ultimately a loser and a fool but with a 'win-at-all-costs' attitude. The title is the lead character's name, 'Christian Tandy'. If I were to give the show a tag-line it might be along the lines of "Christian Tandy... he's the most successful guy he knows" etc.
I don't think a tag-line is essential, but if in one of two lines you can sum up what your show is about and at the same time hint at an original element then, sure, it can't hurt.
I don't think there's actually a text-book method for writing tag lines. I think it may require a writer to be creative or something?
For one of my sitcoms about a homeless transgendered married couple, I used the tagline...
"He's a she, she's a he, and no one gives a shit."
Needless to say, it didn't get very far! 
Taglines are an artform. If your show gets commissioned they'll probably hire a team of shirts-and-ties to find a tagline and they'd probably come up with the one you originally sent in.
It's never easy to find the perfect one. Personaly, I brainstorm around key words that I've identified as needing to be in it.
My comedy is set in the porn world. I played with the idea of calling it a sitcome for a while.
or a sitcum?
or a pornedy...
I'll get me coat...
Quote: Paul W @ February 12, 2008, 4:39 PMI'll get me coat...
You should, it's golden showers out there.
A shitcom based on people into hard & warter sports. A humourous look at people taking the piss. Involves some poo&snography.
Ps. The very best way to write a tagline & I am by no means a specialist is this....tagline....You could Italiac it or have it in bold. I personaly prefer Arial. It brings the word up nice & clean.