I’m sure many of you have seen this Harley Quinn piece by Nicola Scott before. However, these two photos I found on flickr add some nice context to the piece, as it appears it was commissioned at Supanova Perth nearly two years ago. (And having a HQ cosplayer pose with the commission is a nice touch.)
Bonus colour version!

Harley Quinn and Joker (by DTJAAAAM)
Poison Ivy and Harley Quinn (by PatLoika)
A.K.A. Tallest Silver & Kit Quinn at SDCC 2010.
Harley (by jquiz)
Harley Quinn and Joker (by DTJAAAAM)
A rare HQ genderflip - digging it!
WonderCon 2012 (by Kimihiro-kun)