First, a clarification. I said a few days ago that you could apply for an I-539 visa extension if you're in the States on a 90-day tourist visitor visa. My helpful visa lawyer has clarified that this is not the case - actually you can't extend the 90-day Visa Waiver Program (otherwise known as the VWP).
The I-539 allows people who are on a B-2 Visitor's Visa (like, a business visa) to extend their stay but, unfortunately, people on the VWP are unable to do the same. And this would be a bad thing to get wrong - you could end up being unable to get back into the States because you've outstayed your visa.
Here is some information on the VWP: http://travel.state.gov/visa/temp/without/without_1990.html
My bad, folks! It did sound a bit too good to be true....
On another note, I was talking recently to another writer about pitching. We both had a script idea that's difficult to pitch because the story requires a lot of set-up before you can get to the good stuff. There is just too much stuff to explain before the hero can get cracking on his/her journey. Anyway, between the two of us (although Jason, I think it was your big lightbulb moment!), we cracked the solution.
You start the pitch by describing the climax of your movie. So for example, Minority Report, which requires a lot of set-up before the plot really gets going, would begin with Tom Cruise already on the run, a cop convicted of a crime he has yet to commit.
Double Jeopardy would begin with Ashley Judd escaping jail and vowing to kill her husband - whose murder she is already serving a life sentence for.
Or to use a horrendous example, Snakes on a Plane (which took forever to deliver the snakes, let alone get them on an aircraft) would start its pitch with Sam Jackson already battling the snakes on the plane.
Basically, put your hero in a really tight spot - and THEN describe how he came to be there. The audience will be hooked by your opening situation, and then follow your hero on the rest of his journey.
I hope this helps other writers struggling with the dreaded set-up - it's certainly taken the fear out of it for me!