When I run my longer training runs, I use a "Fuel Belt". I have had mine for several years, and I am pleased with it. Mine has four, 6 oz bottles, as well as a pocket that I can store a couple of gels. I also clip my cell phone to it, as well as some pepper spray!

For normal long runs (around 20 miles) I use an Amphipod handheld water bottle. It's designed to fit easily into your hand while running and it was a gift from my sister-in-law who used one during a 100 mile run. Some people like to carry one in each hand for a more "balanced" feel.
http://www.amphipod.com/380/380.html

For trail runs where I want to carry emergency equipment (first-aid kit, whistle, cell phone, water-proof shell, etc.), I use a CamelBak adventure pack (the Octane 14+). It's certainly bigger than I usually need, but it's nice to know that the extra capacity is there for when I want it. Remember, you don't have to fill up the bladder to the full 3 liters!
http://www.rei.com/product/749183

Good luck with your training and race!
Jay

I bought a hip belt where the bottle is at a 45 degree angle in the back. Very comfortable, you don't feel the weight. But that's not enough water for a really long run. Is there someone who could hook up with you on the run and restock your water bottle?

Hi Ann,

I use a hip pack with a bottle holder and a zipper section to hold cell phone, tissue, gu, bar, mace, etc. because I run off-road in the hills. I put the bottle part in front and tie my long sleeved shirt around my waist and behind the bottle, then tie it in front of the bottle to keep it from bouncing. This works AWESOME for me because I HAVE to carry water and necessities. Try it; it may seem cumbersome at first, but you get used to it. Try tying your shirt in different ways. Good luck with your training!;)