Others are more spontaneous. Earlier this month, a column in The Toledo Blade of Ohio recounted the story of a woman who worked at a local mini-mart. When a customer asked her how she was, she said not good - no money to buy her daughter Christmas presents. The stranger handed her a wad of $20 bills, and left.
"People feel a little more sentimental at this time of year," says Mr. Lenkowsky, a philanthropic studies professor.
But the incident in Westborough, a quiet suburb 45 minutes West of Boston that sits on the Rt. 495 high-tech loop, has the added element of anonymity and mystery. The protagonists are unknown and the denouement far from final.
Here is what the town does know, or at least is willing to talk about: The commuter is a 37-year-old man from a neighboring community. The parking lot, which has been a target of crime, has more than 300 slots, all usually taken by 7:15 a.m.
The commuter waited four days before telling police about the incident, after he got the ring appraised. Authorities are not releasing his name. He told them he will return it if someone comes forward to claim it. From there, the mysteries begin.
As people pine for answers, the Westborough Police Department has become the unwitting narrator in a novel everyone wants to know the resolution to. After all, no one else is talking. Whom else do you call?
All this is testing the patience of a department that would rather be solving thefts than talking to producers from Australian TV. The department sits on a quiet street lined with Queen Anne and Greek Revival homes in a town first settled in 1675. On this day, the waiting area - just a few chairs and a few brochures on local elderly services - stands empty. Not the kind of a place used to being in the grip of a national story.
"No comment," bellows one lieutenant to his colleague, who was en route to tell yet another visitor that no more press inquiries about the "ring story" are being accepted.
Two visits later, however, and Lt. Paul Donnelly is talking. At least a little. The lieutenant, whose inbox is topped with a photo of the ring, marvels at the momentum of the story, which has come in between officers trying to handle burglar alarms and ambulance calls. "In 33 years I have never seen anything like it," he says.