I use a Nathan pack. I need a good amount of water still, and one shoulder is hinky enough that it cannot be relied on to grab a water bottle from its side. If I accidentally cause that shoulder pain it's really not fun. So I can't use a belt. I feel a little silly with the pack, but it helps me.
ETA: mine is the Intensity, which is female-specific and holds 2 Liters. The only issue I have had with it is that the "bladder" bounces off the little clippy thing and sloshes around noisily. I've got to Macgyver up a fix for that b/c it is highly annoying. One of the front pockets I put a smaller thing of very concentrated electrolyte drink (I just take extra water when I drink some of that) and then various beans and bloks. The back zippered pocket holds ID, money, keys, etc.
Should also metnion that I have a sensitive stomach and system, and the Dasani usually offered (especially at Disney races) does not agree with me, since it's just local-to-the-bottling plant, filtered, water. So for me it's not a matter of *want* but a matter of "unless you want stomach issues to ruin this run, drink your own spring water that you bring in". If I had a less sensitive system, or when I'm running less than a half and in cooler weather and could trust the course water, I'd just carry my 20oz camelbak bottle in my hand and take extra if/when I came across it.