A member of my family found a roll of new masking tape and a fairly new looking sponga squeeIf nogee rubber attachment on the street. What is the halacha? Can we assume the owner gave up hope of finding them since they are not that valuable? Is one allowed to keep and use these items?
Because it is possible that the owner left the items for a while with intention of coming back to fetch them (depends on how they were found), and also possible that they fell and were not noticed (also depends on circumstances), we cannot assume that the owner gave up home before they were found.
Therefore, if the items were found in a Jewish area, in principle there is an obligation to return them to the owner.
A note should be placed close to the area where the items were found, declaring that the items were found and that they can be returned with simanim (signs). A siman will be the price of the item (if there is a price tag), and the fact that the two items were together.
If nobody shows up to claim the items, they can be used, and their value should be written in an “aveidah notebook” to be returned to the owner should he ever be found, as Rav Moshe Feinstein advises.