does anyone know where I can get a helium weather balloon?
http://www.amazon.com/dia-Professional-Weather-Balloon-600g/dp/B004RK2RAU (http://www.amazon.com/dia-Professional-Weather-Balloon-600g/dp/B004RK2RAU)
Amazon, where else?
..and you can use reward miles to buy it ;)
It appears that the helium is extra.
Here is a main manufacturer: http://kaymontballoons.com/ (http://kaymontballoons.com/) FYI, Hydrogen is cheaper and has more lift. Try not to "Hindenburg" it though. Are you planning a CAP balloon launch?
Major Lord