Just make a couple of notches on the top of a 5-gallon bucket. Set the pipe in the notches, and you have a stable spot for sawing. As a bonus, you can load up the bucket and carry your tools along ...

For instance, Harbor Freight sells its own branded all-purpose, 5-gallon bucket that can help you out in more ways than one. As the Harbor Freight bucket is advertised, it can hold tools ...