This is some advise on doing Public Rituals. I've garnered some of it from discussion lists and some from private experience.

The things to remember in any public festivals are:

1) KISS. Most of the people there have no idea of what is going on so keep it really simple. Don't do anything controversian or subtly symbolic.

2) If there are more than 20 people, no one will be able to hear you. Especially if outdoors, around other noise sources, while facing away so do a ritual that can stand alone without words. Still speak and invoke but, like the silent film stars, exaggerate movements, let the motions tell the story and any spoken parts should simply enhance the event.

i've read a few posts commenting on experiences with large rituals, i'd like to offer some pointers from the perspective of having been involved in planning large public ceremonies for the last year. The Church of Four Quarters in Artemis PA has Full and New Moon services every month, as well as most High Holidays, and here are some of the things we've learned.

1) Unless you plan to be giving instructions during ceremony, be sure to either have handouts available, or a facilitator to give an opening speech. We have found that a facilitator is also helpful in organizing a restive crowd by leading a meditation, starting a chant, or some other preparatory activity to "set the mood" and alleviate boredom.
2) Rehearse your ritual team. Arrange obvious signals for cues, such as lighting a torch. And don't count on candle or torchlight to make gestures visible; it won't.
3) Speak twice as loud as you think you need to, if you're in the center of the Circle. If you're calling a quarter, speak as loud as you're able, even shout.
4) ENUNCIATE!!!
5) Everything takes longer than you think it will, especially just getting the celebrants into Circle. If it takes 30 seconds to smudge one person and you have 60 celebrants, that's half an hour for the first people into Circle to stand around waiting. Multiple "greeting stations" such as a guardian who issues a gentle challenge, provide activity for more people at once.
If you're set on smudging, use two people. A good alternative is asperging; we involve our younger children (6-10 yrs) by giving them this task; with a very large group, the cleansing can be done by the children with the people who are already in place in the Circle, letting the kids work their way widdershins as more people arrive.
6) Group activities, such as a chant to raise power, help the celebrants to feel like part of the process rather than an audience. Be sure to keep it simple (write something on a piece of paper, toss it into a fire pot), because everything takes longer than you think it will.
7) Your group will degenerate rapidly during cakes and ale if they have too much free time; consider posting servers at each Quarter to take a plate and chalice from one quarter to the next. This can be very prettily done by having them come to the altar to receive the plate & chalice from the HP/s, and return them to the altar when they're done.
8) Be sure to have a definite "ending," and it's easier to disperse the group if you either process them out of Circle, or dismiss everything and send them off to another activity (i.e., a drum circle).

I'm sure there are many other tips and tricks, and i'd really appreciate hearing them.