From www.wdwinfo.com

Mickey clouds to appear
Jun 29, 2008

Disney is set to use Flogos, a new special effects machine that creates icon shaped clouds.

Developed by magician Francisco Guerra, the Disney Flogo will send Mickey shaped 'clouds' into the sky.

The logos are created by a foam mixture of soap, water, air and helium which are forced through a stencil. The images can be as wide as 4 feet and can float up to 20,000 feet high and travel for 30 miles.