Q: I received complimentary samples of a product that the manufacturer sent to me by mail. I did not need that product, but thought my neighbor would appreciate it. I tossed the samples onto my neighbor's porch or walkway. If I later decide that I would like to take the product back, can I take it before my neighbor comes home?

A: The Gemara (B.M. 11a) teaches that a person acquires items that are in or on his property, even if he is not aware that the items are there. This is known as kinyan chatzer. However, this applies only if the property is secure or if the person is standing next to his property, so it depends where you tossed the sample. If you tossed it onto the neighbor's porch, it immediately becomes his, and you cannot take it back. [Of course, this is only if the neighbor ultimately expresses interest in receiving the product.] However, if you tossed it onto his open lawn or walkway and he is not present at the time, his property does not acquire the sample, and you can still take it back.