I picked up a cheapy cheapy cutting guide from Lowes a while back and was never real happy with how flexible it was so I decided to take a bit and fix that issue so I could get more use out of it.
For what ever reason, when we moved I decided to cart along 6 or 7 boxes full of good laminate flooring, which just happened to be off print seconds. Got a great deal on them and was easily able to piece together a flawless floor with many "oops" sheets left off to the side.
At any rate, I chose to take three of these and glue them together so that they could be trimmed up to the size I needed.
Once the glue set I fired up the table saw and ripped the glued up flooring straight down the center, giving me two equal boards to work with which were wide enough to have a little "play" room.
Then I moved on to mounting the factory aluminum rails, clamping the rail firmly to the flooring board and putting two holes to either side.
With the holes drilled, the bottoms needed to be countersunk so that the screws did not protrude past the flooring.
With four screws in place, with nuts snugged down well I clamped them to the table saw rail so that I could cut them down to match my circular saw.
One swipe was all it took. The panel was finished, stiff, and would be just what I needed for cutting those long bits of sheet material down.
Shows the factory beside the new one.. I've got both of them done now so I'm ready to rock.
Side note, the circular saw is a Hitachi c7582 which I'd been real happy with. Decided on it because it seemed like a nice mid range with a good, heavy cast base. Works real well and feels very stable during cuts.