Is there some file/directory where kisMAC stores it's Vendor ID's for MAC addresses? If so, is there a way users can ad more?
KisMAC.app/Contents/Resources/vendor.db seems to be it. Looks like a normal plist file. IEEE assigns vendors their OUI (the first three octets of a MAC address). I suppose if you were so inclined, you could fetch the newest oui.txt from IEEE and format it for KisMAC's use. Then you'd have all the vendors OUIs mapped in KisMAC.
It'd probably be *much* easier to just add them by hand. Depends on what you're trying to do. Also, I'm sure Mick has a much better way of keeping up to date with the assignments.