I use a Fuel Belt. They have a variety of styles to choose from depending on how much water & other stuff you want to carry. I like that they have the small bottles -- distributes the weight better than one big bottle. Also lets you mix and match between water and energy drink. I've found it to be pretty comfortable, it's not heavy and I've never had any chafing problems with the belt.
The model I have holds four bottles and has a small pouch for keys, gels, etc. I think there's other companies out there that have a similar product if you want to comparison shop.