In New York and other major cities, I understand, bus accidents are a real problem. Buses turn right and failing to yield to pedestrians. Clueless pedestrians walk in front of buses. I haven't seen any statistics, but I'm guessing that in this era of cell phones and iPods, the problem has gotten worse: not only do such devices distract you, they make it harder to hear warning signs—such as the sound of a municipal bus bearing down on your ass.

I've been a little remiss in writing about one of the best tools for travel I've experienced recently: Ray Samuels Audio's Emmeline The Hornet ($350), a tiny (3" L by 2" W by 1" H) rechargeable portable headphone amplifier. I tend to travel with my iPod packed with hi-rez music files and a pair of low-impedance headphones. That's not a marriage made in heaven, so I also need a headphone amplifier. Over the years, portable headphone amps have gotten better and better while getting smaller and smaller. The Hornet is the smallest I've discovered so far and is my current favorite.

Looking at all of the high-end headphones and headphone accessories available today, it's difficult to even remember how barren the head-fi landscape was in the early 1990s. Back then, headphones got no respect, except for exotic, expensive electrostatic models, yet most of the world listened to music through headphones all the time, mostly through crappy cans connected to portable players. (Well, maybe it wasn't that different a landscape.)

The Emmeline SR-71 portable headphone amplifier ($395) is small but not light. Housed in an extruded-aluminum chassis with a bolt-on faceplate and a rear panel and battery cover that attaches with a thumb-screw, it measures 3.5" by 2.5" by 1.5" and weighs 11oz. That sounds light, especially compared to some of the headphone amps I've carted around in the past—not to mention their four–D-cell extended power supplies—but in the iPod era, it's the portable equivalent of a class-A power amp. So why would anybody be willing to lug it around?