Every one has different hair, so that's a tricky one. I have straight, thick, shoulder length hair. It doesn't have (or ever hold) any curl but I have a huge problem with frizz/flyaway. Sometimes it's like I have thick hair that acts like fine hair. A few products I have found to be helpful are the Control Freak line by Bed Head. I mostly love it for the smell (Pineapple!) It's a tad pricey but I keep it around for special or really humid occasions! There's a "serum" but I've never tried it, just the shampoo and conditioner:
http://www.amazon.com/gp/product/B000G3IGW0
(that's a pack of 2, it was the only good picture I could find, I bought mine at Rite Aid for about $10.)
The anti-frizz line by Dove. The anti-frizz control cream by Dove is particularly great:
http://www.dove.ca/hair/styling/antifrizz_finishing_cream
You can put it on wet OR dry hair, which is great. I always put it on my part before I blow dry and it seems to help with fly-aways.
also good is the Dove "therapy replenishing mist." It is a nice alternative to heavy, creamy conditioners that will weigh how your hair. It is light weight and can also be used on wet or dry hair. I often just shampoo and then follow with this spray:
http://www.dove.us/#/Products/Hair/DailyMoistureMist.aspx/
Aussie makes a great hairspray, it even makes a joke about the humidity of Florida on the bottle, "12 hours of anti-humidity, even in Florida, in your Grandparent's car, with the A/C broken" :lol:
http://www.aussie.com/us/collections/sydney_smooth/hairspray.jsp
I have decided to not cut my hair short for this trip and just do a pony-tail. When I have short hair, I usually have a bob and it just ends up in my face as we are plunging down Splash Mountain. At least with the pony-tail I feel like I'm in control! I do suffer some the occasional pony-tail induced headache, but there are some ways around that like another posted suggested like 2 small ponytails, etc. I do wear a hat sometimes but mostly to keep the sun off my face. I'm one step up from albino and my face can only take so much sun! Also good are a sweat-proof and/or oil free sunscreen for your face. I noticed a huge difference when I started using the oil-free sunscreen, Neutrogena and Clinique both make some good options.
To the poster who said about buying the Clinique anti-shine lotion, I highly recommend it. It's great on my nose because it also makes your pores look smaller and I seem to always have that problem around my nose. As someone who still gets break outs at 25, it doesn't irritate my skin either.