A tough mate, probably one of the toughest. The opponents king must be pushed towards the corner which is the same color as the color your bishop sits on. If you are the one with only a king left always head towards the corner opposite to the bishops color. Most will give up and allow a draw.

I love this mate because it is so fragile.

 --- --- --- ---
|   |   |   |BK |
 --- --- --- ---
|   |   |   |   |
 --- --- --- ---
|   |   |WK |WN |
 --- --- --- ---
|WB |   |   |   |
 --- --- --- ---  
Take your time with this ending. First bring your opponent's King to one of the board's edges. Second drive the King to the appropriate corner. Keep the knight and king beside each other (this prevents your opponent from attacking the knight) and cut off your opponents path away from your object corner. Use a well timed zugzwang to force your opponent to make moves he/she would rather not make. Use the bishop to deliver the checks and ultimately the checkmate.

I have never seen this ending occur. I came across it while going through endgames and liked it. I use it as a good drill for understanding coordination between a bishop and knight or king and knight.

Endgames in Chess
Chess Openings
Chess