I offset my flying emissions but not on the spot when I book. I do it once or twice a year in a lump.

In all fairness, there was a NY Times article the other day saying that offsets aren’t all they’re cracked up to be because they either a) take too long to offset the emissions, or b) encourage people to fly. My take: FTers are going to fly one way or the other; they might as well do it. It’s more responsible than doing nothing at all.