When people ask me for directions someplace in the city (Boston, Somerville, Cambridge, Arlington) or how long it will take, I usually respond with something like, "Well, I bike there, so it takes me about 20 minutes. If there's a Red Sox game tonight and you're driving, it'll probably take you 40 minutes."

-Or -

"You could just jump on the bikeway and be there in 30 minutes..." or some such thing...

It's just my way of throwing it out there. I try not to pepper the same people over and over, but I remind them every now and then of how easy it is.