http://www.nikonchat.com/nikon-compatible-flash/

PZ42N Sunpak Flash for Nikon DSLR?
OK … maybe I do not understand anything about flashes … I thought to use iTTL and so on, are needed a SB600, SB 900 dedicated flash … now, the Sunpak claims can support iTTL. Is this true ….. Sunpak maybe this is not compatible with wireless flash system?? I'm not very knowledgeable about flashes … anyone can point me in the right direction? Should I get the SB600 for my Nikon D80?
If you do not support command mode, then you might want to stick with Nikon flash units.