Street Strider: The offspring of an all-body elliptical machine and a three-wheeler, the Strider uses arm handles, foot platforms and an eight-speed internal hub drive-train to propel you at bike speeds.
Likes: The first of several ellipti-bikes set to hit the market soon, the Strider isn't just a home run; it's a grand slam -- maybe the most exhilarating aerobics machine I've ever tested. Best of all, it's practical as daily exercise for almost anyone of any fitness level or weight. Blending the smooth, satisfying all-body workout and standing position of an elliptical with the mobile velocity and range of a bike, the Street Strider combines outdoor adventure, fitness and ease of use, with a bird's-eye view that makes you feel as if you're soaring in the breeze. In a two-hour, 20-mile ride on the bike paths of Irvine and the Newport Back Bay, I climbed steep hills, made fast descents, got dozens of smiles and thumbs-up from adults and kids, and was clocked at a regular cruising speed of 14.7 mph by a passing cyclist. Halfway through, I ran into another happy Strider rider, Shay Sorrells, a recent contestant on "The Biggest Loser" TV show (now weighing in at 325 pounds, down 150 pounds from her peak six months ago) who said she rides hers at least an hour a day.
The device folds up for transport and fits on a roof rack. There is a minor learning curve of five or 10 minutes with the steering, as you must lean to turn, somewhat like skiing.
Dislikes: It's heavy (51 pounds), bulky ( 71 inches long, 28 inches wide and 54 inches tall) and not cheap.
Price: $1,995. (800) 348-0998; www.steetstrider.com.
RowBike: The hybrid row-cycle invented a decade ago by Scott Olson, founder of Rollerblades, has a sliding seat, stationary foot pegs and pull-bars attached to an eight-speed twist-shift drive train.
Likes: Exhilarating. Rowing is a great all-body workout, and doing it at 20 mph on land is a thrilling joy ride that gets you sweaty fast and hammers the shoulders and butt. It makes you realize how little exercise your upper body gets on a normal bike. Seeing cyclists do double takes added to the specialness. The steering, like the Street Strider, requires a short learning curve that involves more leaning than turning. I felt as if I could ride for hours, and probably could have; two years ago I saw one in France's 750-mile Paris-Brest-Paris ride. The standard 20-inch-wheel model fits everyone up to 6 feet, 2 inches, with bigger wheels available for taller folk.
Dislikes: Taking one hand off the wheel -- say, to drink water or eat a cookie -- makes the machine unstable.
Price: $1,188 (20-inch wheels), $1,290 (26- and 24-inch wheels). (877) ROWBIKE; www.rowbike.com.
Revolutionary Rocket: This ingenious semi-recumbent bike from North Carolina inventor Alex Hunt is propelled by both pedaling and pushing-pulling a movable handlebar.
Likes: Great workout, super fun, fast and comfortable. It flies uphill, as if you're on a regular bike with an extra motor -- your upper body gets a real workout. Pumping legs and arms at once, you quickly get into a flowing, fast-paced rhythm as the handlebars, atop a four-bar linkage that keeps them level, move back and forth 3.5 inches. That motion moves a long chrome rod that drives an auxiliary crank attached by a small chain to the main crank at the bottom bracket. Steering is normal whether the bars are moving or static, as they are during coasting on turns or steep descents. The comfy body position with low pushed-back seat and high bars mimics the chopper position of the Electra Townie.
Price: $2,300, with a $1,695 limited-time special; tandem $4,300; (336) 207-1767; www.revolutionaryrocket.com.
The Treadmill Bike: It's a human-powered treadmill on 20-inch wheels from prolific Canadian inventor Brent Curry.
Likes: Different. Unique. Attention-getting. It's perfect for those who are tired of running in place or, as one Canadian reviewer put it, people who "like to run but are afraid of the ground." It's tough work staying balanced on a belt set at a steep 8.7 degrees, which makes for rigorous walking or running, especially on climbs. But getting to the top is worth it, as you can blow past old-fashioned "ground" runners.
Dislikes: At 7 feet long and 77 pounds, it does not fold-up or travel well. Slower than conventional running.
Price: $2,011 ($2,500 in Canada); (519) 576-3350; www.bikeforest.com.
Wallack is the author of "Run for Life" and co-author of "Bike for Life." firstname.lastname@example.org