I have a 550Ex flash and want to buy 2 or 3 - 580 ex's. Then i could shoot multiple flashes (on small stands with the new battery packs attached) in wedding venues etc. Is this as basic as buying the equipment and setting them to the right channel. I'm not talking about technique but the purchasing of the stuff. is there a better option?
Yes, you can control the remote flashes using your 550 or 580 if they are on the same channel. You could also get an ST-E2 wireless transmitter to do the same thing too, and it is much lighter and more convenient.