I'm not a spy, but I've been using gear you might associate with 007. New matchbook-size cameras that clip to your tie or shirt let you capture a day's worth of encounters, then upload them to the Internet to be remembered forever.

Why on Earth would anybody want to do that? After trying out two devices that recently began shipping, the $279 Narrative Clip and $399 Autographer, I think the answer for many will be why wouldn't you?

Yes, I took gigabytes of boring photos of me sitting in front of a computer at work. But when I took the tiny cameras hiking or hanging out with kids, they produced Instagram-worthy shots. (I also discovered surprising uses, like when I scanned my photo log to discover where I'd misplaced my watch.)

Wearable cameras are a potential solution to the growing annoyance of people holding their phones in front of their faces throughout birthday parties, concerts and other important moments, instead of just living them.

But there's a cost to amassing so much photographic evidence. The tiny cameras made others uncomfortable when they found out they were being recorded. Some friends wouldn't hug me; gossiping colleagues kept asking, 'Is that thing on?' These devices upset a fundamental (though arguably flawed) assumption that even in public, you aren't being recorded.

Makes you squirm, doesn't it? One reason I wanted to review these cameras is that this kind of technology isn't going away. 'Always on' cameras are becoming popular in home electronics like the Xbox One and a new wave of streaming video security systems. Now you can buy cameras that attach to your wrist, ear, bike helmet and eyeglasses.

The two cameras I tested are meant for everyday use. On the surface, they seem very similar: plastic clip-ons that silently take photos and store them until you upload them to a phone or computer. They arrange the photos in a contact sheet on your phone and use software to highlight the most interesting shots, or give you a sped-up video of your day.

The Narrative is the least obtrusive. It could be easily mistaken for a tie clip. The Narrative has no buttons or screen, and just one function: It takes a photo of whatever is in front of it every 30 seconds, more than 2,000 a day, with quality comparable to the iPhone 4's camera.

A sensor makes sure the photos are always upright, no matter how the clip is oriented, while a GPS chip inside notes where you are each time it takes the photo. Tap on the Narrative twice and it will snap a photo right away.

The pricier Autographer is three times larger, making it flop over when I attached it to my shirt pocket. It packs a 5-megapixel camera with fisheye lens and five sensors -- including an accelerometer, compass and thermometer -- in order to take a picture when it thinks your surroundings have changed. It can use Bluetooth to transfer shots wirelessly to a phone or computer right away. All of this extra tech means the battery lasts about 10 hours, compared with the Narrative's 30.

What are you supposed to do with all of those photos? More than 1,000 shots taken on my hike this Sunday weren't worth keeping. But 15 were delightful, unposed shots of my friends and their kids at sunset. You can't get a 7-year-old kid to look that naturally happy with a regular camera pointing in his face, but the candid camera did. I could imagine taking one of these cameras to special events or on vacation.

Judging based on price, shape and battery life, the Narrative would seem to be the better product. But after using both cameras, I realized the Autographer was superior because its design better respected my interactions with friends and strangers alike.

Very few people noticed I was wearing the Narrative's tiny clip. It made me feel like a creep for not disclosing to friends and people on the street that I was photographing them. It offers no indication it's taking a picture and continues snapping away unless you turn it over or put it into a pocket (which you need to remember to do when you go to places like the toilet). After wearing it for a few days, I decided to tape a camera icon on it.

The Autographer announces itself as a camera. Each time it snaps, a faint blue light flashes on its front. More important, its lens is highlighted by a bright yellow circle and has a rotating cover so everyone can see when it is and isn't watching.

In short, Autographer's design helps keep people from being jerks. The fisheye lens means you can't accidentally take head-on photos of people unless you are very close to their faces. Since the camera connects wirelessly to your phone, you can review your shots right away -- and delete shots if anybody asks. By default, Autographer only saves all your photos on your computer or phone rather than its own servers.

All these concerns are rooted in civility. There's nothing actually illegal about using one of these cameras in most venues in the U.S., outside of restrooms, casinos and other businesses that expressly forbid them.

Narrative's Swedish creators say their clip wouldn't make a good spy camera because it isn't as small as the latest snoop gear and its 30-second automatic timer is too arbitrary. Also, their research found people who spotted it did generally understand that the device was a camera. 'If you want a camera to spy on your friends, we don't want you as a customer,' company co-founder Oskar Kalmaru said, 'And we intentionally made the Narrative Clip bad for use in cases like that.'

The U.K.-based makers of Autographer take the extraordinary step of including an etiquette guide in its box, with suggestions like 'pause your image capture if you are in proximity to people you don't know for a long period of time.'

For me, wearing either camera meant I was constantly on guard, ready to turn it off if a situation became too private to capture.

We might eventually get used to the idea that we're being constantly watched, but for now I think a baseline rule ought to be some kind of notice: I'm taking your photo.

The experience made me realize we need a big public conversation about how to live with ubiquitous sensors. Part of that means developing criteria to judge technology beyond basic hardware or software design. Let's call it the 'relationship test': How does this piece of technology change not just my life, but how I interact with you?