It is a sports bottle that has a large twist on top for filling and a smaller twist on top that you drink out of (this is kind of like the pull up top of some of the sports drinks or the dish detergent bottles.) A filter fits inside the smaller hole. When you drink the water goes through the filter and magically tastes pretty good. I don't like the water in Florida and with the bottle, it doesn't taste any different from the filtered water from my refrigerator. It is well worth the money. You will need to change the filter after a certain amount of gallons, but it has a decent life span.
I put ice in mine each morning and will ask at food places if I can get ice and water (removing the large cap with filter first). I've never had anyone say they can not do this, but I always ask following purchasing a meal. You can also fill the bottles at the water fountains. The bottles are not insulated, so ice will not last a very long time, but the water will taste much better using the Brita. You can also buy bottle straps from the vendors selling water in the parks. This way, you can put the bottle over your shoulder and forget about it. The bottles seal, so you do not have to throw your drink away to enter an attraction.
Hope this helps.
-Jockaroo