I'm using a white piece of foam core. My image size is 22 x 37 and we've cut the foam core to fit that. The table is only 41 inches across anyways and my projector is set up to drop the width going across the table. I haven't really played with making the picture size larger or smaller. I'm currently at about 5 1/2 feet on the throw distance.
We could throw the picture down the length of the table except I've got a rather large hanging light fixture that hangs directly over the center of the table. You can see the edge of the hanging light in one of my first pictures about 5 posts up. It has 5 fifty watt bulbs but the light from it hasn't interfered with the projected picture. As it is, we have to slide the table a little towards the kitchen by about six inches to get clearance for the projected picture.
I've been planning on putting a grid on the foam core. However, if the pad at staples is near those dimensions, then I might pick one up. It would be a lot easier than having to draw my own grid and then worrying about the foam core getting damaged.
We started out with the whole inn and courtyard showing and then zoomed in for scale. During the adventure I scrolled the picture and used the mouse as a pointer.
As always, any tips or suggestions are welcome. This is my first laptop and projector. I made the decision to make the purchase based on this thread so I figure you owe me Steelwind.
I cannot stress enough how easy this has been. I'm looking forward to your projector guide and trying some other mapping systems. I bought Gridsmith about two to three years ago and hadn't used it much since it sucks up ink to print out color maps. I'm going to project some maps made with it next week.
The players love the whole setup. I've been dropping in sounds and background music during the meetings using the laptop. When not using a specific map, I drop some artwork down on the table for visual help.