So, I rented some pocketwizards today to try them out and the guy there told me I had what I needed--once cord and two PWs. Great. BUT What if I want to fire my on camera flash at the same time as the off camera flash? Do I need 2 cords? My flashes are a 580 EX and a 580 EXII. Also, on the 580 EX you can turn the dial to "off" "master" or "slave"... do any of these options allow me to NOT need to use another cord? I'm new to the off camera lighting thing and would appreciate some help from you all who know what you're talking about! I really want to experiment with this tomorrow. Thanks!

Oh yeah... maybe I wasn't clear with my question, but is there also a way that I can wirelessly sync without a PW because of the "off" "master" or "slave" options? If so, can the EXII do this? How can I make them sync to each other?

Sorry for the scattered question! My brain is fried...

Yes, you need two cords.
I just got some too and I dont really know all that much except, you can plug your trans into your camera and the other end into the "sync in spot on the PW" and put your EX on your hot shoe, then velcro or screw the PW onto the bottom of your camera. Make sure both are in the off position(no master or slave).
Put your EX II on your stand or wherever its going then plug your reciver into it (same off position for master/slave thing) and voila!
Thats all I know..

Typical configuration is to put the transmitter PW on the hotshoe, then connect the receiver PW to your flash via a cord. This is what the guy told you--one cord and a set of PWs. One thing to remember is that you will not be able to use the remote flash in TTL mode. All the PW does is to fire the flash, so you'll mostly likely need to use the flash in manual mode (full power, 1/2 power, etc)

If you want to fire the on-camera flash as well, then you'll have to connect to the transmitter PW via another cord.

I believe when you have your flash in the "slave" mode, it will fire when it "sees" another flash firing. You'll have to check your manual to see where to place your slave flash. On some flashes the sensor is off to one side and so it may not work if it can't see the other flash (i.e. the sensor is not facing the other flashes).

But yeah, play with it and take some notes and draw some diagrams. I find it to be a good way to remember these setups...

Reminds me of a story... some photog was setting up this rig at a tourist site with many many strobes for a commercial shoot. He was using optical slaves to fire the lights so he'd only need to fire one main flash and all the others would go off. Just as he was done setting up the whole thing, an old couple walked up and thought this was interesting and decided to take a picture of it. They pulled out their little point and shoot, pushed the button, the little flash went off and triggered the _whole_ rig...