No, not these. These:
It's the footer/column for our deck posts - a Sonotube, a cardboard tube for pouring concrete columns, set atop a Square Foot, which forms the footer for the column. So instead of pouring footers and waiting for them to cure and then pouring the columns, you pour the whole thing in one shot. (Craig found the Square Feet through Dan Cook, a real cool guy at United Rentals in Frederick, MD.)
The guys at the site set these forms today (I am on vacation! - more on that later); concrete should come anytime. Then we can get going on the deck. Sounds like the electrical meter/panel connections are finished, as is site grading and the pump for the well.