Beaded necklaces are the symbol of Mardi Gras. Everyone wears them, and everyone tries to get even more from the partiers on parade floats who literally toss out tons of the trinkets to onlookers as they wind their way through the downtown streets. Beyond the beads, float riders also let fly candy, toys, stuffed animals, souvenir cups and, as an appropriate salute to southern cuisine, moon pies.
There is a trick for gathering more treats. Many of the parades pass the same location twice, or close to the same location two or three times. If you look at the parade routes beforehand, looking particularly for where a parade might pass within a block of its return route.