I have a lot of pics from events, unfortunately it's been difficult to get any good "promotional" pics. The best camera to use is a digital SLR, especially one with good low-light capabilities. My camera pales in comparison to what a digital SLR can do. Also, the best pictures show the screen, the audience getting ready, and some of the surroundings. The problem is that this usually means it is too light to see a projected image on the screen. I've seen many people photoshop images on the screen, but I think that misleads the customer into thinking that "daytime" movies are possible.
The picture below is from an event last year using a 16' x 9' CB screen. When I took the picture I was standing up on a hill, and this unfortunately makes the screen look smaller (in my opinion). Also, this particular crowd sat further back than I think they needed to.
I don't do very many events each year with my 20' screen, so I have fewer pictures of that set up. Also, the bigger events tend to keep me more busy, and therefore taking pictures isn't always on the top of my mind.
Is this the kind of picture you are looking for?
I took a quick stab at cropping it a little. After looking at the picture above, I thought it might look better if there wasn't as much of the trees showing above the screen. Also, I thought it might appear to be a bigger crowd if I cropped the bottom out a little. That way the crowd might "appear" to be larger than the picture shows. This event ended up with about twice the number of people you see, but it certainly wasn't a HUGE crowd.
Here's the cropped version:
Of course the above picture is no longer in "standard" picture dimensions. I'll look for some more if this is the kind of thing you want. Also I can supply you the originals instead of copying the ones above (I reduced them in size just for posting).