Ever eat out at places like Subway, KFC or McDonalds (and a few others besides)? If so, go and have a quick look here at the Washington Post's calorie counter- simply select what you'd normally eat and a horrendously high figure will appear to tell you how many calories you're consuming.
Pretty scary. My only consolation is that when I grab a 12" meatball Sub I usually eat very little for the rest of the day. Looks like I'm going to have to cut down even on that.