If you don't have an MSR drom, you should.
Key Points:
- Bomb proof!
- Has rope around the perimeter making it easy to mount to nearly anything.
- Hydration profile so you can slip it into packs.
- They make a hydration hose for them.
- Only store how much water you need to, so you might as well get the 10L.
- Perfect for setting up water caches.
- Amazing for moto and backpacking trips.
- Though I can't recommend it, you can use them as your secondary gas storage on adventure motorcycle and overland trips. Some forum user on thumpertalk or advrider tested them for holding gasoline.
- Easy to fill from any water source.
Overall these droms are an amazing tool and something I take on every trip.