There's a live parade cam at Napolean and St Charles and lots of videos and pics like this one online in the Times Picayune. Watch Drew Brees as Bacchus thowing little golden footballs to the crowd during the Rex Bacchus parade Sunday.
Foodie Ellen Kanner in Huffington Post skims the fat for meaning:
French for Fat Tuesday, it's not just cheap beads and anonymous orgying (not that there's anything wrong with that). Mardi Gras is the day before Ash Wednesday, when Catholics begin the Lenten 40 days of penance, prayer and cleansing before Easter. Traditionally, Mardi Gras was a night of eating rich food, the better to endure the lean days of Lent. New Orleans embraced the concept with typical passion. It seems like half the regional recipes start with a cup of heavy cream (not that there's anything wrong with that, either). ...
Food goes beyond the plate. There's its traditions, how its sourced, its romance and history, the powerful associations it evokes. You can't eat these things and yet they deepen your experience and appreciation of your food. They add their own spice. They make you care. ... Food at its source tastes of the spirit of a place and in New Orleans, that means laissez les bon temps rouller.