Evergreen 747 Water Bomber conversion:

Saw a reference to this while flipping through a Aviation Week & Space Technology magazine this weekend:

What gets me is the way the 747 visibly starts to lift from the shooting aircraft as all the water leaves the bomber.

See also this longer video.

Claimed capacity: 90,000 litres. By comparison, the CL-415 capacity is just over 6,000 litres. The Martin Mars conversions operating on Canada's west coast have a operational capacity of around 27,000 litres.

Wikipedia suggests the Evergreen is not oprational, due to the US Forestry Service wanting bombers to deliver fire-retarding foam instead of water; the retardant is denser than water, and this means a full load in the Evergreen would be heavy enough to cause concerns about the aircraft's service life.