Joking aside I believe it varies by hotel. I would check in the hotel forum you plan on staying at, or let us know what hotel you are staying at and we can let you know based on that info.
Welcome to the boards The drinks are poured into small plastic glasses at TTR, so if you are a fast drinker (who isn't at TTR?), you'll be headed back for a refill before you even reach your lounge chair. If you're a slow drinker, you'll be drinking warm cheap booze. Not a good thing. Most repeaters bring an insulated mug of some sort with them. The best kind has a wide mouth and a lid that comes completely off, and a little flip thing that covers the drinking hole in the lid (or that you can stick a straw into). If you don't have a lid, you risk getting Sexy Pool water into your drink. Again, not a good thing. I prefer to drink thru a straw (obviously this is best for slushy or mixed drinks, not beer!), and if that's your preference, don't buy too tall a mug or the straws will be too short. I guess that's a long answer to a simple question (how typical of me!), but given the amount of bonding time you will have with your instrument of frosty beverage delivery at TTR, you want to get one that works well. I bring a little travel shampoo bottle of dish soap with me to wash my mug every night. You don't want to have to use the bar soap in your room (leaves a perfumed taste in your mug). If you are drinking blended drinks, your mug can get rather skanky pretty quick. Once again, not a good thing.
Yup like Karen said, an insulated cup with a lid. Go for one that is unique, then the boys at the bar or the servers will know it is yours. Ours are a woodgrain finish (SS inside) and Wendy just holds them up at the bar they reach over for them and fill them knowing already what goes in them. Same with the pool servers, if I leave my cup with lid off on a table it gets replenished.
Tervis makes a great cup...keeps cold drinks cold and hot drinks hot. Check out their web site, you can get them custome any way you want.
Yes at TTR they give childrens glasses. If you do not bring a mug or large cup, they do sell them at the store. Or, you can always order 2 drinks at once. One word of advice I heard after the trip that I wish I knew the trip was this. Your room gets 1 bottle of water per day. DO NOT throw the bottle away. You can bring it to the bar and have them refill it. Enjoy your trip!
Water I actually bring an insulated water bottle with me and fill it up in the morning from the bottled water in the room before going down to the sexy pool. I don't always remember to drink it (!), but at least when I do, the water is cold. If you bring the plastic water bottles down to the pool, the water will be warm in an hour. They don't hand out bottled water at the bars, just in your room.