CindyBeth, we have used some of the defoggers, but some sting our eyes, DH and I both wear contacts when we dive. We have one type that doesn't sting, but I don't think it really works better than plain old spit, as disney6 says, and it is much more expensive.
We used to have scuba fins that we wore with booties, leftovers of BC (before children) when we used to dive, they had amazing kick in drift dives or surf. They were huge and heavy and destroyed in a basement sewage flood. We replaced them with US Divers snorkel fins, much easier to lug around. It is nice not to lug the booties around, too. This was before the cheap availability of beach shoes. It is sometimes nice to have booties and fins if you are doing a lot of rocky beach entries to dive or snorkel. You can walk over rough rocks then don the fins once you are in the water. We don't do this with the kids, just use clear beach or boat entry. If we walk tide pools we just use beach shoes from Target.
Gloves (and probe sticks, a short pole with a wrist strap) were also leftovers from dive days. They can be used to GENTLY handle marine life and the probes can be used to push off rocks in heavy surf. This is also something we do not do with the kids. We teach them to touch NOTHING in the water, sensible in light of the deterioration of our coral reefs. I still occasionally wear garden gloves just to protect my hands.
Also mark all your stuff with Sharpie markers, when a bunch of stuff gets shed around a dive boat, it can start to look the same. I'm also hunting for some type of bright tape to swirl around our snorkel tops so I can easily recognize all of us in the water. Rear ends and snorkels look the same in congested snorkel areas. A dive snorkel is usually marked with red at the top, but the cheaper discount store types are not as distinctive.
Silly Mojomanny, you really have to dry off before using the kleenex, or you do end up with a salty wad of goo, not just due to nose stuff.
Oh, and P.S., try to go light on the sunblock, apply it an hour before you go in the water, wear a t-shirt to protect your back. Huge amounts of sunblock are very toxic to the reefs. Some places, such as Xel-Ha near Can Cun, even require a shower before entering the water.
Carla