Aluminum can?
Archery target.
Cut up and hung from poles, can be used as a flashing scarecrow. Birds don’t like getting flashed in the eyes any more than pilots do.
If it’s a tin can from, say, frozen peas, it makes a decent saucepan, or for the obvious, a storage container.
It’s conductive, so it can be also used as a makeshift wire, or cut, flattened, and sandwiched with mica (or oil paper or wax paper or any other non-conductive dielectric) to make a tuning capacitor (or condenser, depending on what side of the Atlantic you’re from) for a crystal radio set.
If it’s an old beer or soda/pop can, you can cut the bottom off of two of them (of differing diameters) and make a jetting alcohol stove (I forget what these are really called).
Many many many more uses I’d probably never think of in the field.
Next up: Rusty automobile leaf spring