Old olive trees with their picturesque trunks can be conversation stoppers. The olives can be processed as green olives (unripe) or black olives (ripe). Ripe olives can be pressed to extract oil. Unprocessed olives are not edible. Uncollected olives are staining pavement, and can generally create a mess.
Olive trees can be sprayed to prevent blooming and then then fruiting.
Many people are allergic to olive pollen (or contact with the leaves) and non-sterile variety are forbidden to sale in several locations of the western USA. Sterile varieties generate a much smaller quantity of pollen.