Luggage Tags (quality ones)
Key rings (quality metal ones like what pfizer used for Viagra)
Lighters (not PC I know) nasty ones or limited Zippo
Pens various (cant go wrong as used by all pilots, loadies, dollys and ground crews well the literate ones anyway, or for defacing rear galleys)
Mugs and tea cups (obvious)
Stuff for golfing ie Tees,Driver head covers etc (good for all the Capts) plus hip flasks in a limited line to help get some of the old boys to the 18th
T-Shirts and Polo shirts with tastefull logo size and placing.
Trucker style ball caps (the ones with the net back and foam front) with the PPRuNE logo on a shield.
Stickers (for those funny square boxes all pilots carry)
Model planes with PPRuNe on the side and tail (as to which type to use that is a whole thread)
Thats all I can think of just now hope this helps.
Maximilian