This is why I use a bike with quadruple chainrings up front and 30 gears on the back for trips to the library or the bar.
But seriously, the whole "wow, you only have one gear" thing is somewhat common from people who see a serious roadie and look down to inspect the bike and see only one gear. I've gotten everything from "hey, it's just like the old bikes" to "how do you get up hills", but hey, it's always cool to be able to picque the public's interest in these machines and educate them a little.
Viva la singlespeed revolution!