I'm about to purchase a few Pocket Wizard Plus II. I'm goint to be using it with a 580EX II and SB-28. Do I need to purchase anything else to make it work, like cable, etc?
I'm not 100% certain, but I don't think the 580 (or the SB-28) has a PC sync socket...so you might need a cable to hot-shoe connection at the receiving PWs.
The hotshoe adapter fits onto the first unit. You unscrew the existing hotshoe and screw on the one with cable. Attach the adpater to it and plug it into the PW. This will enable the 580 to be triggered.
The SB-28 should have a PC port on it, so you would just need to attach the included PW cable to this port and you are in business.