Again, AMS has them. I used one about 6 months ago on an 8 hour layover (purposefully long layover, so I could visit the city.) Think it cost me something like €3 or €4 to leave a carry on-sized rollaboard for the day... again it's €5/day to leave any item at the counter. Pretty good deal if you have a long layover in AMS, especially with the 15 minute train ride to the city costing all of €3.60 (and I think there's a same day return ticket available for something like 1.25x - 1.5x a one-way.) That annoys me when I take something like the Heathrow Express or Narita Express or Arlanda Express. (Yeah yeah, those airports are a bit further out and the trains go much faster...)

I've seen them in some other airports, but I can't recall the last time I saw one in the US.