any particuliar reason of 1/16 watt? 1/8 and 1/4 are easier to get and will work just fine unless you need the 1/16 for space reasons
and you want SMD or axial? if you need SMD i suppose you might be able to find one on some some old computer cards/boards, but you should be able to fit a 1/8 if its axial
also you might want to check radioshack, though their website seems to be down right now