I just saw this product on an episode of Doomsday Peppers and wondered:

-has anybody tried it?
-what's the advantage over just filling your tub? (My first thought was that it would keep falling debris, dust, bugs, etc. out of it)

FYI (standard no affiliation, etc... just curious!)
http://www.waterbob.com/

I would employ the water in the tub, as long as I treated anything I used for cooking or drinking. Still that is a pretty decent price - You can pay that much for three or four 5 gallon jugs easily.

What I've read about them is that it's impossible to clean and dry them after use, which makes them a single-use item. If you put only clean water into one and figure out a way to dry it out so that there's no mildew, you're good to go.

an alternative option....I have an old frame house with single bath.. during hurricane season, without power, it gets pretty hot, and a shower is a welcomed opportunity to cool off...I use a 33gal trash can placed in the rear of my tub/shower for non potable toilet flushing if need be (it has been quite a few years since we've lost city water, but it has happened when sanitary sewer lift station have lost power and flooded, contaminating the water supply)... by not using something like the Water BOB, I have a place for water storage, and still have access to my shower drain...

We discussed them on another forum I'm on and the subject invariably turned to using it without it being in the tub. Under those conditions I don't think it would hold up at all and would weigh a ton. I think I'll just stick with 55-gallon drums.

I bought one for my mom for Xmas but she hasn't tried it yet.

haven't looked at the dimensions, but as 2005RedTJ commented.. you need to consider the weight

a cubic foot of water is 62.4#
a cubic meter (say close enough to 39.4"x39.4"x39.4") of water is a metric ton... 2200#

100 gallons is 800 pounds, more or less. Do I think my house could stand an 800 pound gorilla sitting on the sofa? - maybe.

But if it can't be cleaned, why have one?

I know I wouldn't want to try to MOVE one across the floor when full. That kind of weight in a plastic bag?

At $20 it's supposed be a single use item. They market it as a temporary storage solution for forseeable situations, I think. Things like a hurricane that will make landfall in a certain timeframe. Obviously it's not a very good solution for regular long term water storage.

Of course, it's also not great for a complete unexpected interruption of the water supply. But hey, it's twenty bucks...