Mates in 2, 3 and 4 moves

Hi there,

The 3 puzzles below shouldn't be difficult to solve. I got the ideas while playing a game. If you see something wrong with the puzzles or if you find a refinement, please let me know!

1. Black to move and mate in 2

That's what I could have missed during the game! I didn't see it immediately because, as you'll probably understand, I was myself focused on finding a mate for white.

And now the mates in 3, which are not much more difficult to solve.

2. White to move and mate in 3

For this one, I saw the idea one move too late. 

[UPDATE: 2011.05.26]

And now, this is the mate in 3 which I finally found at the right time, even though the game finished one move earlier than planned. I modified the position because white's advantage was bigger than that and some of you probably wouldn't be motivated to find the shortest solution if you had other ways to win.

3. White to move and mate in 3

That's it for now!