I can't say you'd need this in your shop, but with all the people currently and in the future building shops I thought maybe some of you could use this jig to help cutting your vinyl siding, and soffits.
This is something I started using about 12 years ago to rapidly cut vinyl siding, vinyl soffits and aluminum soffits for my houses and garages that I install siding on.
It is relatively cheap and very easy to build. I originally started out using a 2x10-14' but it turns out to be too long of a jig for my current pickup and I use a 12' instead and I don't seem to miss the extra two foot all that much.
To make it you start out with a 2x10, screw a 2x4 on the backside that is the same length as the 2x10. At some point towards the right end I attach a 2x6 cut on a 45 degree on both ends, the reason for the 45 angle is to screw some fasteners into the 2x10, then add a short 2x4 to match up to the back rail. Then I determine the rate of travel I need for my circular saw and cut 2 pieces of steel windbracing to act as guides for my circular saw. I square the guides to the back 2x4 and space them wide enough for the saw to travel back and forth smoothly. You will need to put a wood cutting blade in your saw for it's first pass through the 2x4, and set it to a depth to just cut into the 2x10.
In some cases a extra width of 2x6 may be needed depending on width of material to be cut. I attach a broken tape to the back rail, having pre measured where the tape needs to be fastened, remember vinyl travels with heat and cold so this measurement does not have to be to the 1/64th inch to work....maybe within a 1/16
For siding the tape works well to align the siding up to the dimension you want and cut with the circular saw which has a plywood blade in it on backwards...cuts better that way for me.
For repetitive cuts on soffits I place a nail at the dimension I want and just start cutting away at the soffit stock.