Question:
I have read several threads and related articles as to save money by bringing in your bottled water from the outside. Maybe even freezing a bottle for later in the day. If someone was wanting to BE cheap but not LOOK cheap they might bring in the brand of water that WDW sells from the resturants and stands. Not that I am cheap in disguise; this is for a friend of mine of course.

What brand of bottled water may be purchased in the various parks and is it the same brand in all locations?

Answer: From what I can remember correctly, they now sell Dasani water. But, bringing your own water (whatever brand) is surely no problem - I've personally taken in different brands without a problem for years - and then I got a great tip from someone and have done this for quite a while - I bought one of those unbreakable Nalgene bottles (the kind used by hikers, etc.) and fill it with whatever beverage I'd want (usually water or Crystal Light) and throw it in the freezer a few hours before I head out. They can also be frozen overnight - but MAKE SURE not to fill it to the top - it could explode in the freezer. Either that, or if you don't have access to a freezer (or don't have enough time) fill it with ice. Then, take a towel and wrap the bottle in it. It'll sort-of insulate the bottle, keeping the contents cool for longer, AND you have a nice cool towel to use to wipe yourself down! On hot days, I'll even carry a facecloth - you can ask the outdoor vendors to dip it in the ice water that the drinks are stored in, and voila! you've got a nice icy-cold towel.

I took an insulated sport drink bottle, one with a wide mouth screw-off top, one liter size. It had a clip on it, but it banged around on my hips so much when clipped to a belt loop and pulled your shorts down so I just carried it. I filled it with icewater in the morning. When it got low I just walked up to a food service place or vendor and asked for a large cup of ice and refilled it. As the ice melted, cold wonderful water. The CM's were all nice about it. As mentioned already, plenty of people do it. A bottle of water is $2.50. I will admit I am cheap when it comes to certain things, but will splurge on purses, shoes, sheets and furniture. Quirk of mine.