Food and running goes hand in hand, you cannot run without food and well food is more enjoyable if you can run some of those calories off.
So that being said, I think there needs to be a little introduction to running and food, specifically the technical foods:
Runs an hour or less:
Liquid: There is no need to Gatorade or any other replacement drink. If you feel you're in need of something, then cut orange juice by 50% with water. If it is boiling hot and you are sweating like crazy my suggestion would be to pick a different time to run.
Gels: Don't need them, you have enough glycogen in your muscles
Runs longer than an hour:
Liquid: I would still opt for either watery Gatorade (watered down powdered mix) or a watered down 100% fruit juice until you're up to a run that is 1 1/2 or that is really warm. This is not to say that Gatorade doesn't have its purpose it definitely does, it just gets abused a lot of the time.
Gels: You can - I would say if you know it's going to be closer to two hours that when gels are really needed. That being said, don't wait until you think you need one. It is on these runs that you are going to be testing out any race day fuel needs. So that being said go to your nearest running store buy a few packages of gel that you like or think you might like. Personally I'm bland when it comes to these things, I want vanilla or unflavoured. Make sure to try a few brands and if you need the jolt, there are ones with caffeine added. I personally can really only tolerate vanilla flavour by GU but their lemon/lime and unflavoured are also tolerable.
So now that you have your gels, pick one, and at the hour mark of your two hour run, take a 1/3 of the package and then every 1-2 miles take another 1/3 - while washing them down with WATER. I am aware that GU states that their gels are to be consumed all at one time, I find that my stomach violently rejects this policy.
I have found this is the best way to make sure my stomach doesn't freak out about having new contents that require digesting. It also helps your brain belief you are keeping the energy coming, that way you can efficiently wage the battle of the "I feel so drained" or whatever else your brain will be telling you.
You don't have to pick gels either there are other options ranging from eating fresh dates to sport beans to potato chips and M&M's. Personally in that spectrum the only thing I can get behind is Sour Patch Kids - bizarre yes, but they're small enough to suck on and I find the sour refreshing.
Photo: http://ncrunnerdude.blogspot.ca/2009/05/sports-gels-galore.html