Personally, I'm a firm believer in the first ten pages (about the first ten minutes of the film, give or take, it depends on the content - action sequences usually take longer than dialogue based scenes) being able to draw a reader in, so that's what I've tried doing on two of the three scripts I'm currently working on (the third doesn't even have a "FADE IN:" yet so bear with me). In one instance, we have two gunfights happening in two locations on the far side of the world to each other (well, Baghdad and the UK, which seems pretty far to me), which can be best described as chaos (I did use... somewhat stronger language, shall we say, to describe it in the script, but I'm trying to keep this as clean as possible). The other has a bombshell (somewhat literally) dropped about two thirds of the way down page 8, which is always a good thing.
One thing I've heard most people tend to forget is that after the front 10, there's still about 100 odd pages or so to go! (I will admit, very much guilty of that on my part, I tend to get my beginning together, slap the ending on it and then spend shedloads of time working out just what goes in the middle). This is not a good thing to do. It's all well and good having a beginning of a film that rivals James Bond for it's action and intensity, but if it then peters out over the remaining 100 pages then, sorry bub, but your script pretty much ain't worth the paper it's written on. Which means that, if your anything like me, you've just wasted a bucketload of ink and paper getting the thing printed and a sack of cash buying stamps et cetera trying to get it seen by people. Actually, seeing as the only scripts I've ever finished are five minute shorts which were for an assignment I had to do for college last year and thus printed them out at college, I've never actually had to spend the cash on printing and ink cartridge replacements. Good job too, I'm skint!