Walking backward while talking is useful for leading a tour, demonstrating a moonwalk, or retreating from a room full of ominously staring toddlers. See the reverse saunter put to good use with today's Groupon: for $125, you and up to five friends get a two-hour personal tour with Acorn Tours of Boston (a $250 value).

Acorn offers tours that vary by length, sites visited, and neighborhood, based on clients' preferences. Grab up to five buddies or lonely nail technicians and venture along the Freedom Trail, swinging through such sites as the Old State House, which is the city's British-government headquarters; the Paul Revere House, the oldest residential building in downtown Boston; or the Old North Church, where two lanterns warned Paul Revere about impending British troops and sitcom-character breakups.

Browse neighborhoods such as Beacon Hill, an affluent and historic district, or conga line through Back Bay, which is replete with boutiques, the Boston Symphony Hall, and the Museum of Fine Arts. For all tours, knowledgeable guides can pick up tour takers at their hotels or the Cheers bar in Beacon Hill.