I love my Fuel Belt - no bouncing at all, very little sloshing, and the weight is distributed around your waist. Mine has 3 small fluid bottles (the equivalent of one large water bottle), and a gel flask. There are models that have more bottles, and some have a little pouch for keys and snacks and stuff. It was great for marathon training the past 2 years, although a model with more bottles would be good for really long runs (I try to plan my routes so I can refill at some point).