I had a hydrobak, didn't really work out for me.
Browsing the local wal-mart I was back in the bike section and found one made by "Next" It's great, very well constructed, has nice wide straps and even has the one to go around your waist. Holds 2 liters, has plenty of storage space for tools and whatnot. Cost around $30.
The one disadvantage, it has a spring loaded bite valve which in and of itself is really cool, I prefer it to the camelbak design. But, since it's designed for bicyclists it tends to not pull water into the hose as well, so you might have to suck or either stand up and lean forward. Other than the it's really cool :)