A great use for those empty 1 and 2 litre bottles is to make them into bird feeders. This can be done by simply cutting a smooth, round hole in the side, toward the bottom of the bottle, and filling it with seed. Turned away from the prevailing wind, it will usually stay dry and snow free. Hang with a piece of wire or heavy string.
The feeder simply threads onto the bottle and disperses seed as needed. I use black sunflower or “oil” seeds. The birds prefer them to regular sunflower seeds and they are easier to break open. Finches relish niger seed, but at $1/pound, they’ll have to be content with the sunflower seed. :)