Running is supposed to be a 'minimalist' activity - Shoes and go.
However nowadays we tend to have more and more stuff, water, gu, gels, phone, heart rate monitor, ipod, at least.
Some days I use everything, some days I go minimalist. I wish I could go minimalist all the time, but here are a few of my faves.
1: Water belt - I always have my "Nathan" with me. If you ran with me, and didn't know who 'Nathan' was, he is my water belt. haha
I hate having to carry water constantly, even when I race, but its a necessity for me. Runners strive to be lean, lighter and faster. Sucks that all lbs lost are just negated by the weight of the belt, water and other stuff.
I was doing 2 mile loops on a semi warm sunny day. I wasn't thirsty, hot or tired, I was actually feeling really great. I paused every 2 miles when the loop ended to drink. By mile 6, I paused to drink then everything turned white and almost fainted. I knew this wasn't good. I laid on the ground until colors returned. It was a very frightening experience especially since I was alone and without a phone.
This is why people pass out during races. I always thought, if you're tired just stop. Except you Don't "feel" tired, hot, or thirsty at all. Your body is running on fumes and you don't even know it. I've done that route many times and even longer routes without water and was fine, but this experience was enough.
Nathan Elite 1 Mutation is a great water belt. It runs small, I wear a size 27, and a Med barely fits with 1-2 inches give. The size listing on the product site are wrong. *Make sure to get one with a Velcro Strap and not a buckle!
2: PowerBar Energy Gel Blasts - Whatever you choose to eat on your runs is really up to preference. I like these gummies because they're tasty, and easy to chew. Strawberry Banana and Raspberry are yummy!
5: Heart Rate monitor - I have a Nike and a Garmin and now I want a Polar. My advice is get a really LIGHT watch. Both my Nike and Garmin ended up quite heavy and I only use them when cycling. Even though you can't feel the few ounces it weighs, when you're running long distances that tiny weight multiplies 10 fold and you can really feel it in your shoulder or elbow.
6: Polar HRM + Nike+ Nano - I want to add this Polar HRM to my Nike+ ensemble. And I wouldn't need to wear a watch! Nike really knows how to sucker me in.
7: Swimovate Pool Mate Lap counter - this isn't running related, but cross-training related. This watch counts your strokes and your laps without needing to push any buttons. Its pretty awesome because I always lose count and always forget to push the buttons.