Top Woodworking Tips - Stair gauge cutting guide

From The FamilyHandyman.com

Use stair gauges as a crosscut guide
Stair gauges are usually used to lay out stair jacks. You clamp them to a carpenter's square to match the rise and run of a stair jack and then mark the notches. But if you put them both on the same tongue of a carpenter's square, the combination makes a great crosscut guide for circular saws.

Versatile and inexpensive
Pick up a pair for less than $5 at any hardware store or home center. Clamp the square in place so it won't slide around while you're cutting. You wouldn't like that one bit.