Much more fun than the parade (yecch, Ouest de Paris) are the bals populaires!
Most of the uniforms at bals populaires traditionally belonged to pompiers, who at the time were all firemen, though of course now there are pompieres as well.
Here are some photos of the bals, and some nice pompiers! http://tinyurl.com/zc5nv
There is also a huge bal at La Bastille, of course (ha, Est de Paris!)