I'm new to off-camera flash photography, and this question confirmed my guess that you don't have to have off-camera flashes of the same brand; but I need a bit more info.
I've got a Canon 40D, Speedlite 430 EX II, and Sunpak auto 355AF (an old Pentax flash).
The only setup I can think of to get both flashes to fire off-camera are 2 wireless receivers (hooked up to flashes) and 1 wireless trigger (on 40D).
I'd like to hear if there are any alternatives to set these 2 flashes up off-camera; and some wireless trigger/receiver recommendations.