I’ve owned a Nikon SB-28 since my analog days and added a Nikon SB800 when going digital. Advised by Strobist, I added a third flash – a Nikon SB26.
To get all those flashes going off camera, I bought some cheapo Cactus (AKA Gadget Infinity) flash radio triggers – those can be found at eBay for just a few dollars. I initially bought two receivers and when I added the Nikon SB26 to my collection, I bought the third one.
I really like those cheapo triggers and up until now they were lots of fun (see this shot, I just can’t miss a shot at showing my son off). Of course, if you need high reliability, you should consider the big brother: Pocket Wizards.