First there is the water barrel. Available in sizes from 15 - 55 gallons, these are pretty easy to store and are very versatile. *Note: One thing to consider is that water weighs almost 8.5 pounds per gallon. A 55 gallon drum filled would weigh over 450 pounds. Make sure they're supported on a sturdy surface. The best thing to do is get the barrels used. Syrup at cola bottling plants come in these containers, as well as other food related liquids. You can get these for free sometimes if you talk to the right person, they usually throw them out. If you can't find free ones my local Rural King sells them used for $12. Check locally but if all else fails you can always order offline.
If you get creative you can find places around the house to hind them in plain sight. One of these in the living room with a piece of plywood on top (cut in a circle) with a sheet draped over it would look like a regular table. On the Preparedness Pro Facebook Page there is a photo posted of using them to create a bed with wood on top of the barrels then the mattress and sheets. I've also heard of people using them for a computer desk. It would make them easy to get to if they were in the living room or bedroom. Just make sure you have a good hand pump to get the water out.
There is a company that makes a product called the Water Bob. It is a large plastic bag designed to fit in a bathtub. The bag is made of strong, and safe plastic with a hole to fill it with. The idea is that in the event of an emergency, you put it in the bathtub and can fill it with up to 100 gallons of water. This is a great product, and for the price it's great to have in the closet. They fold down into a small box to there's no problem storing them. The only problem is see is if you wake up with no water at all then you can't fill them up. This would be great to have along with your existing water storage just to give you a few extra gallons in the event you might need it.
At most Wal-Mart's you can purchase these 7 gallon Reliance water containers. They're blue containers that come with a pour spout and a convenient carrying handle. They usually run around $12 each and I have quite a few of these full of water. They are great quality and are a great way to store water in small amounts. Even if you have all your water in 55 gallon barrels you can keep a few of these to transport water. They will sit on a table and you can use the included spout to pour water with ease.
I talked about this in my post about "Free Water Storage" but I will mention it again. If you drink a lot of juice (and you should) then you're going to end up with a lot of empty jugs. Juice bottles are perfect because they are easy to clean, just wash and fill with tap water. These will store for years and is a great way to add just that much more water to your water storage without costing you any additional money.
One thing to also remember is that your hot water heater is essentially a tank full of water. In an emergency this can also be tapped into for drinking and cooking. Most hot water heaters have a valve and nozzle at the bottom for draining. It would be a good idea to have an attachment with a hose on hand so you could dispense the water without risking a spill.
There are also larger water storage solutions available if you have the space. You can get containers from 100 to 300 gallons or more. If you have a barn, or garage with the space this might not be a bad idea. Just make sure you have a way to transport the water into your house for use.
There are probably a few things I missed but this should give you an idea on how to store your water. Water is more important than having food. You can go 3 weeks without food but won't last 3 days without water.