I found this nice little problem on Tim Krabbe's website the other day. I found it so unique and beautiful, that I felt compelled to share it here as a puzzle to be solved. Please do not use a computer and do please don't look up the answer! Try to use your own brain power!
It's White to move and reach a winning postion in 7 moves.
Gady Costeff (Israel), 3rd Place, World Chess Composition Tournament, 2003