I finally bought a little hand-held wind-a-ma-jig. No more boasting about the hellacious SF Bay winds with no proof -- now, when I tell people what a manly sailor I am, I can point to my cute little yellow gadget and say, "see, half a gazillion knots!!!".
Sailing Pro Shop gives a 20% discount for Sailing Anarchy members so even with the $7 shipping fee, I saved $28 over Worst Marine. Follow the clever links if this appeals to you.