Strong adhesive, and strong fasteners
925249
I don't think I'll ever use velcro again. These things GRIP. I used it to mount my EZ-Pass to my windshield. (The EZ-Pass already had the strips on it, and these fasteners matched those strips.)
780756
Secures very large packages to my cargo rack.  Strong hooks.  I think that if I had two of them, there is nothing that I couldn't bring home on my bicycle.
1028188
REALLY strong...REALLY.
Great for holding pieces of plastic together while I glue.

Fragile, break easily because they pop together from the strength of the attraction.
3564381
Solid build, easy to attach. Well worth what I spent
2703077
I received these yesterday, and instantly started putting them to use Here are my thoughts:
PROS:
Durable, strong construction. Just the right size for all of my charging and misc. cables. Adhesive backing is strong, and adhered right away. Multiple color and size options available, I chose black because thats just my preference, but I am thinking about more in different colors to either match the surface attached to, or to color-code my cords.
CONS:
More of a warning, when opening the package, and removing the backing to expose the adhesive, make sure you have pushed it onto the clip first, as I believe from the factory they are not pressed too hard onto the clip.  I only mention this, because I almost pulled the backing off. So, not a con, just a warning!
I rely on amazon for reviews of nearly everything before I buy. I like to give back to the community by reviewing items myself. My reviews are always honest and accurate to my experience, with that in mind, this item was sent to me for a discount in exchange for an honest review. I have thoroughly tested it and my reviews are always 100% honest and are not affected by the discount given.
1305514
These are so useful - and the magnets are quite powerful.  I use them to hang tons of different things - and they are very strong.  Put a piece of painters tape on the back if you don't want to scratch a surface (like your refrigerator!).
4500358
These are a very convenient size and really strong. They are heavy duty and the different sizes are very convenient, also.
1614118
Strong stuff! I first bought it to fix an iPod screen. But now, I'm actually using it to mount decals to car paint that don't normally have adhesive. In the attached picture is a Ford Ranger XLT nameplate I found in a junk yard. After spending about 35mins layering the adhesive, I then mounted it to my vehicle with nothing but the tape. It's been on my vehicle for over a year and a half now and held up against all kinds of weather including snow, rain, and sand. I highly recommend this product!
4443585
Working under the truck I can slap them to the frame and keeps me from losing bolts and screws. They are even strong enough to hold some of the smaller wrenches for easy access. I've got three of these and use them to separate different parts for different work areas on big jobs. e.g. One tray for radiator bolts, one for the AC fan motor assembly, and one for misc. screws.
4152559
Higher quality than I expected--these are great. I thought they'd be flimsy little cheap things, but they went on very well and are sticking strong. Solid material, good adhesive. Perfect size.
2873533
I bought this to support two 22" widescreen Dell LCDs that I use for day trading.  The standard pole that is included allows me to raise the screens quite high for easier viewing over my desk clutter.

The mounts are very strong, and the pedestal is very stable.  However, you must use an allen wrench to adjust the vertical tilt of the screens, and the bolts must be very, very tight to keep the monitors from flopping forward.  I am a strong guy, and they gave me fits.  Plus, the screens move as you tighten the bolts, so you have to fudge a bit to get the angle just right by the time everything in cinched down.

I'm happy now that everything is set up, but I'd buy another stand if it were easier to adjust on the fly.
3506410
I bought this size and the next size up, 3x4 or 3x5. I have a mountain of screws, nuts, washers, and bolts, standard and oddball sizes. NASA calls me when they need additional fasteners. So, here's the skinny:

Weight - way strong enough for a workshop, home or otherwise, strong closure (think Ziplock). Hold a surprising number of small parts and fasteners.

I organized all my screws, nuts, washers, and bolts and hung them on a peg board like you see in Home Depot. Now, if I need a fastener, I can just gaze at the maze and find it quickly.

Small Parts has a better price and a smaller quantity option then other sellers I found. I recommend these bags.
419522
VERY strong, much better than other similar. they do break fairly easy if dropped on a hard surface. once installed they are fantastic.
2 are fairly easy to seperate, 4 together are very hard to get apart. Be careful about where you put them, they will attract any metal within 1 foot.
3924488
adhesive is holding up much better than i expected, they are definitely meeting my expectations.
2075136
Easily installed, fastens well, lights are bright
1571444
I like these and the Scotch Heavy-Duty Fasteners. Both work well inside, but I have not tried either outside. I think these hold more weight than the Velcro, or need less to hold the same weight. But, you get more with the Velcro. Probably couldn't go wrong with either, honestly.
1401101
just what I needed, great price for a lot of anchors and screws