When Advertising Executive and native Bostonian James Ryan, 52, got the itch to revisit his city's historic sights, he shrank from the prospect of whizzing past them on a crowded tour bus. Solution: he popped a prerecorded tape into his personal cassette player, consulted a small map that came with the tape, and set off by himself on foot.
While the tape used such sound effects as chanting crowds and pealing bells to dramatize pre-Revolutionary War events, a relaxed narrator guided Ryan along Boston's Freedom Trail, even anticipating his questions about the locations of telephones and restrooms. Ryan rated the tour "first...