Piloting a 21st-century Segway through the streets of Colonial Annapolis, David Smith is a true time traveler. He rolls through streets once strolled by Washington and Lafayette in a natty three-cornered hat, knee breeches and ruffled cravat, surveying the scene through wire-rimmed spectacles. His attire, right down to the buckled shoes, is period-perfect, but his noiseless two-wheeled ride is an eye-catching anachronism -- one Ben Franklin, that able inventor, never could have imagined.

Smith leads Segway tours of Annapolis for Segs in the City, adding a historic fillip to an accelerating trend. In the mid-Atlantic, tourists can also take guided city journeys by Seg through Philadelphia, New Jersey beach resorts and Corolla, on North Carolina's Outer Banks. (Washington has Seg adventures through a branch office of Segs in the City, operating from Bike the Sites at the Old Post Office Pavilion, and City Segway Tours, from the Willard InterContinental hotel.)

Segway Human Transporters have come into vogue worldwide as spiffy sightseeing vehicles -- a surprise, perhaps, to inventor Dean Kamen, who designed them for personal travel. Disney World has more than 120 Segs, and hundreds more are employed in city tours from Sydney to San Francisco.

Maryland's 17th-century capital certainly wasn't designed for cars, but its flower-filled sidewalks easily accommodate the compact Segs, and they up the cool quotient on traffic that ranges from inflatable Zodiacs in the harbor to bass-thumping convertibles uptown.

On a recent summer afternoon, I donned an aerodynamic black plastic crash helmet in place of a tricorn and set out to enjoy a spin.

Annapolis Segway safaris depart from Randall Street, a block from the city's waterfront hub, City Dock. Owners Tonia Edwards and Bill Main, who started the operation in April 2004, offer one- and two-hour guided glides around town (plus one led by the Colonially costumed), preceded by some easygoing instruction in the art of electric ambulation.

Edwards, a congenial Aussie, offers just the right mix of tips, reassurance and humor to make riders comfortable on their machines. "It's all about leaning forward," she explained. And indeed, once you get used to the fact that there are no brakes and that turning can be a heart-stoppingly swift maneuver, Seg skills can be mastered fairly quickly. A brochure aptly describes the process as "intuitive, but not instinctive" -- which might explain why helmets are required.

We started our Seg journey with a 10-minute in-store demo covering the basics (turning the machine on, stepping onto the platform and steering through cones), then practiced a few figure-eights, street-to-sidewalk transitions and full stops. Fortunately these were conducted at a comfortable 6 mph, still fast enough to stir a welcome breeze on a muggy Annapolis day.

Perched one step off the ground on the Segway foot platform, riders can swoop through alleys, ride up ramps and occasionally duck under ladders that they might not notice on other city tours. Like electric wheelchairs, Segs are officially restricted to city sidewalks and crosswalks.

One unexpected bonus of a Segway tour is that it's a pure ego-booster. On these wheels, a trip through town seems like your own personal homecoming parade. Everyone, it seems, loves Segs, from the admiring Japanese tourist who calls "Nice car!" to the delighted driver who squeals "I want one of those!" from an intersection. "We have lots of kids chasing us," Edwards admits. And the occasional barking dog, too.

Soon we were gliding up Prince George Street, ducking under a leafy limb or two as we headed for the restored William Paca House. The city landmark, one of three homes of Declaration of Independence signers in the capital, has a staid Georgian facade that conceals a two-acre terraced garden, now at its summer peak.

At College Avenue, we paused at the lush front lawn of St. John's College, founded in 1696. Each spring, it's the site of a hotly contested croquet match between the Johnnies and midshipmen of the nearby U.S. Naval Academy. (Alas, the academy, subject to post-9/11 security restrictions, is not part of the Seg tour.)

Feeling more confident by the block, I was almost ready to relinquish my grip on the handles and dispense a regal wave to smiling passers-by. What kept me humble -- and focused -- were the planters, front steps and upheavals in the pavement that loomed like video-game hazards. As we powered on, we rolled past the 18th-century Reynolds Tavern, which still welcomes patrons, rounded Church Circle (home of St. Anne's, a venerable Episcopal church) and swung by the State House, the oldest in continual use in the nation. We peeked through the gates of the governor's mansion, hoping to see young Drew Ehrlich practicing soccer, before descending to the harbor via Main Street.

Once we'd completed our trip, we earned a Seg "license," which allows future Seg rentals without a guide. Edwards said many fans return ready to buy a Segway. "They're great toys," she said (and, at about $4,500, more affordable than your average Hummer).

The advantages of touring by Seg are obvious: Compared with walking, the Segs allow visitors to travel faster and cover more ground. And for those with limited mobility or stamina, they can be ideal for sightseeing. Smith, the costumed Colonial guide, regrets that more older people don't try them. "Senior citizens would be the biggest beneficiaries of Segways," he said.

Smith, himself a Segway owner and true believer, leads the midday Colonial history tour for Segs in the City. "This State House is where Washington resigned his commission as commander of the Continental Army, and where the Treaty of Paris was ratified -- very important historical events," he pointed out. "On this tour, we can stop and talk about them, and if someone really wants to go in, we just lock up the Segs and do it."

Not everyone comes for the history, of course. "We work out beforehand what people are interested in," Edwards explained. "I'd say about 80 percent just want to ride the Segs and find out more about how they run."

In Annapolis, Edwards and Main provide the Seg experience for a mix of clients, all 14 and up. "We had a group of four who were all over 65, and we often have couples who are in town for a B&B weekend," said Edwards. "People who've ridden with us in D.C. come here and do it."

The couple began their Segway venture as dealers but now confine themselves to tours and hourly rentals (limited to those who've already proven themselves on a tour). Come mid-November, they'll close up shop until next spring: "In winter, we like to run away," Edwards confides. In the meantime, like their customers, they're enjoying the ride.

Annapolis tour guide Howard Buffington takes a training run on a Segs in the City segway. The company offers tours of the historic Maryland capital, some conducted by costumed guides.