I did this last year or the year before, I forget, but it was pretty fun. Its really hard to take pictures if you are not actually in the parade. The side lines are crowded, and you can only take pics of the paraders on the sides. If you grab a costume, you can actually enter at the start, and walk the route leisurely inside at a slightly slower pace and get lots of shots, which is what I did last time.
The start is also a good place to snap pictures, as the floats and groups are just standing around, you can mingle within them and get nice shots.
I will try to go this year if I get my costume figured out lol. I might be able to meet up if I can get out of work early as I usually get out 8-830.