I was kindly invited to a 15mm Napoleonics game with my friend James the other day. Normally we would use the old Shako rule set, but James had picked up a copy of Black Powder for a bargain price on eBay, so we thought we would give it a bash. Doubtless we made a few mistakes, as you do when learning a new set of rules, but we quite enjoyed the game.
James has a sizeable collection of 15mm Napoleonics which we could use, and I brought along the few of my Peninsular British that I have actually got around to painting up. In the end it was a French vs British/Portuguese/Spanish force. We didn't get to run the game to a definite conclusion - I can say that the French skirmishers didn't come off so well against the Rifles though :-)
Here's a few pictures, on James' tastefully "old school" terrain, of the game: