I'd say I was startled, but the fact is that I knew from a newsgroup post that the spanking scene was there somewhere. 
Yesterday afternoon I went to see this comic book - style film Shoot 'Em Up starring Clive Owen (yum!) partly because I like cartoonish violence, partly because Clive Owen was in it, partly because there's a spanking scene. I got to go with with someone into spanking who I know from Shadow Lane -- something fun but also nervous making as I always have a hard time meeting new people (he ended up being a delightful movie companion.
The film was about a B- to C+ (for me, lower for my companion who gave it a D as he's apparently not got my crush on Clive). There were a number of reference to different kinks and fetishes (including breast feeding), but the main spanking wasn't done in a fetish context at all, something which made it ever so nice for me.
Below this point could be considered a film spoiler so fair warning.
The set up is good -- Mr. Smith (Clive Owen) spanks the woman partly as a diversion -- the pretext is a mother is yelling at her child, smacking him and threatening him with a spanking. Mr. Smith goes over, scolds her for hitting her child and then publicly spanks her about 5 times, supposedly to show her what it feels like. While the spanking is not done OTK, it *is done* in a way those of us who've been smacked in public over clothes might remember.
Short, sweet and worked for me. Not a great film, but getting to watch a spanking in a vanilla film not done to mock the fetish and watching it with a spanking friend was worth the price of admission for me.
Of course the fact I've had spanking fantasies about Mr. Owen since Closer did help.
