UPDATE: The cult idea is generating a fair amount of interest. I've already gotten some great suggestions. Here is a summary:
The Cassini space probe's field recordings from the atmosphere of Saturn will serve as the cult's anthem. Cult members will subsist by collecting the rainbow sap that the deities inject into the trees as a gift. The cultists will then bottle the sap in baby food jars and sell it in the parking lots at music festivals. To sell the jars, signs will be printed in the Papyrus font listing the price and medicinal properties of the sap (eg. antiperspirant, cures cancer, quitting/starting smoking). All profits will be divided equally and spent on food, camping equipment, and musical instruments. Depending on their rank, cult members will live either in the tops of trees or in hollowed-out logs on the forest floor. Everyone will be required to wear the same tennis shoes, sunglasses, and smocks.
I'm happy to incorporate any additional ideas, just so long as I am the leader forever (or until after we go into space and find the source of the rainbows). This is going to be a great cult!
UPDATE 2: More ideas from the comments! The cultists will move about the mountain while doing the space-girl dance. This will also be the dance of worship. A portion of the profits from the sale of the rainbow sap will be used to "buy off" the local officials so they don't shut the cult down. And along those same lines, the cult will need to stockpile guns to defend its private property.
UPDATE 3: The cult will purchase a power generator and a DIRECTV subscription so all members can watch television deep in the forest. No one will fight over what channels to watch because everyone will have their own miniature television.