I would probably rely on liquid carb intake (e.g. Gatorade) during a half because generally they digest better IF I could trust a) the person mixing it or b) the person handing it to me. Neither of which I generally can. So I usually carry a gel. I suggest if think you will be out there for longer than 1:50, you carry one and less than that, just take one. Unless you are training for a longer distance event and want to practice you may want to try and take an extra.
Make sure you take a good 2 cups of water to wash those gels down. And plan ahead so you're not surprised by the aid station, you have your gel out and ready to dump.
Let's take the example of the Santa Cruz Half Marathon to plan a nutrition strategy in advance.Click here for the course map where the aid stations are marked with a bottle.
So for slower than a 1:50 goal time I would take a gel at 5.5 miles (Station 3) and 9.5 miles (Station 5).
For less than 1:50 goal time I would take a gel at 8 miles (Station 4).
This race a couple of years back was a bit of a mess. They started half an hour late and they tend to use dopey kids as volunteers so if you're super stressed about your nutrition you might consider bringing your own water and be prepared to have to grab water directly off the table. But you should be OK.