you might just want to contact them. As a graphic designer, I can say that they are in breach of Copyright and either need to pay you for use of this image or should have contacted you for permission.
Or you could just be flattered by it and let it go
Heh I am flattered and amused. May drop them a line - if only to find out where they got it from (I suspect it was Tastespotting...in which case the copyright issue might be a little more complicated, perhaps?)
I'm just slightly disappointed they photoshopped out some of the blisters