There is a Cancer Council "Invisible" Zinc that works pretty well. Lot cheaper than the original stuff. Usually I lose the stuff before I run out of zinc in the tube.
Yep - I have very sun sensitive skin and I second the Ella Bache zinc-based waterproof foundation recommendation - a high % zinc and never worn it off yet. I was a bit surprised at the asking price for such a small tube (probably quite standard for cosmetics...), but Michel is right - you work a little bit a very long way. I apply a very thin layer of EB zinc before driving to the beach, and use a top-coat of standard pharmacy zinc just before heading out - it gives a lot more protection in the summer months vs pharmacy zinc alone. That should bring out the metrosexual in you.