The camera, it turns out, was the most immediate draw for the roughly two dozen users I spoke to. It’s the simplest thing to do with the device, and everyone experimented avidly with the new angles and picture-taking moments it made possible. Video calls — the real-time sharing of one’s point of view with others — were also popular. In Maine, a surgeon named Rafael Grossmann used Glass at work: he wore his device while inserting a feeding tube into a patient in the operating room and streamed the video live. Normally, he says, only a handful of students can cluster around a teacher, making it hard for them to see from the surgeon’s perspective. “To have someone else see what I see — it’s just amazing in surgical teaching, in medical teaching, in mentoring someone through a problem,” he says. Later, Grossmann reversed the arrangement, having an I.C.U. nurse wear Glass during a procedure while Grossmann and another surgeon offered advice via video call.

Because there isn’t an app store for Glass, its capabilities were initially limited by the few applications preinstalled by Google — sending and receiving texts, taking and sending videos and pictures, getting directions and doing Google searches. (The company says an app store is coming next year, when Glass is available to the general public.) Google created a set of guidelines for designing applications, and by midsummer, private developers had produced a few offerings. A cooking application, for example, displays pictures to go with a recipe as you make it. “It’s like a little chef alongside you, telling you what to do,” says Gary Gonzalez, a petty officer in the Coast Guard who was chosen among the 8,000.

Cecilia Abadie, a software developer in California, craved a way to make a to-do list, so she created an app called Glass Genie. “Because I’m a working mom, I have my kids asking me things all the time,” she says. Other users figured out ways to get Glass to display notes. Before I went into meetings, I began e-mailing notes to myself, then leaving them on-screen as virtual Post-its.

Many users discovered, as I did, that Googling on Glass was less useful than they expected. It sounds so alluring in theory: all human knowledge, right in front of your eyeball! I had success with simple queries, like checking the weather or finding the title of the next Junie B. Jones book. But Google’s intention to make its computer “glanceable” and “out of the way” also makes sustained reading difficult. When I spent much time looking at Google results, my eyes got tired from looking upward. (The same was true for videos: more than a minute or two was wearying.) I soon abandoned Googling altogether. One user, Zoë van der Meulen, claims that the relative hassle of a Web search on Glass is a feature, not a bug. She describes Googling on a road trip with her husband and says that if she had done it on her phone she would have most likely checked Facebook or Twitter at the expense of interacting with her husband. “I think it’s way less distracting than the cellphone,” she says. I discovered a version of this effect with my Twitter usage. While using my laptop, I used Glass to show comments directed at me personally. But I otherwise ignored Twitter for hours, and paradoxically this meant I was less likely to lose myself in endless Twitter-surfing. It certainly looked ludicrous: a guy sitting at a computer, with another computer on his face. But it did the job.

My own concern about distractions ran in the other direction: the wearable didn’t interrupt me enough. Glass was so busy trying to stay out of the way that it wasn’t as useful as it could have been. I originally hoped to use Glass in the manner of Starner and the other wearable pioneers — as a note-taking machine, a commonplace book grafted on to my consciousness. But the software for that doesn’t exist yet. At best, I could dictate a note that Glass would send to my Evernote account, but I couldn’t search my files or e-mails. To access their pre-existing collections of personal notes and mail through Glass, Starner and Priest-Dorman had to hack it, installing a version of the Linux operating system on the device. Then they used their one-handed keyboards wirelessly, allowing them to type instead of relying on voice recognition.

Other Glass users had reactions similar to mine. Josh Highland, a software developer, says that he was hoping — unrealistically, he knew — for “Terminator vision,” or vast amounts of text and data scrolling into view the way they do in the “Terminator” movies when we see things through Arnold Schwarzenegger’s cyborg eyes. “I expected it to be always on,” Highland says. He says that in trying to prevent too many interruptions, Google overshot the mark. As scholars of multitasking have found, not all distractions are bad. Certainly switching between two unrelated activities can wreck your focus: try playing Angry Birds while listening to a lecture and you’ll do neither well. But if the flurry of alerts and apps you’re juggling are all focused on one piece of work, that might be useful; the distractions are the work, as it were. Like most adroit users of technology, Highland generally tries to avoid diversions. After trying The New York Times and CNN apps on Glass, for example, he quickly turned them off. He didn’t need a news ticker in his eye.

Ultimately it’s difficult to assess how a tool like Glass might change our information habits and everyday behavior, simply because there’s so little software for it now. “Glass is more of a question than an answer,” in the words of Astro Teller, who heads Google X, the company’s “moon shot” skunk works, which supervised Glass’s development; he says he expects to be surprised by what emerges in the way of software. Phil Libin, the C.E.O. of Evernote, told me that my frustrations with Glass were off-base. I was trying to use it to replace a phone or a laptop, but the way head-mounted wearables will be used — assuming the public actually decides to use them — will most likely be very different. “This is not a reshaping of the cellphone,” he added. “This is an entirely new thing.” He predicts that we’ll still use traditional computers and phones for searching the Web, writing and reading documents, doing e-mail. A wearable computer will be more of an awareness device, noting what you’re doing and delivering alerts precisely when you need them, in sync with your other devices: when you’re near a grocery store, you will be told you’re low on vegetables, and an actual shopping list will be sent to your phone, where longer text is more easily read. Depending on your desire for more alerts, this could be regarded as either annoying or lifesaving. But as Libin puts it, “The killer app for this is hyperawareness.”