Here's a wild bishop sacrifice!

I played this one last night ... I never know quite what to do against 3.Bc4?  Any ideas would be appreciated ...

[Event "Live Chess"]
[Site "Chess.com"]
[Date "2011.06.30"]
[White "Am*****"]
[Black "greg_b"]
[Result "0-1"]
[WhiteElo "1580"]
[BlackElo "1518"]
[TimeControl "5|0"]
[Termination "greg_b won by resignation"]

1.e4 c5
2.Nf3 d6
3.Bc4 e6
4.h3 a6
5.d3 d5
6.exd5 exd5
7.Qe2+ Be7
8.Bb3 b5
9.a3 Nf6
10.O-O O-O
11.Bg5 Re8
12.Qd1 Nc6
13.Nc3 Be6
14.Rb1 c4
15.Ba2 cxd3
16.Qxd3 b4
17.Ne2 g6
18.a4 Bf5
19.Qd1 Qd7
20.Ned4 Nxd4
21.Nxd4 Rac8
22.Bb3 Bxh3
23.gxh3 Qxh3
24.Qf3 Qxf3
25.Nxf3 Ne4
26.Bxe7 Rxe7
27.Rfd1 Nf6
28.Ne1 Re4
29.f3 Re2
30.Kf1 Rh2
31.Kg1 Rh5
32.Kg2 Re5
33.Nd3 Re2+
34.Kf1 Rh2
35.Nxb4 h5
36.Nxa6 h4
37.Nb4 h3
38.Nd3 Rg2
39.Nf2 Rg3
40.Bxd5 Nxd5
41.Rxd5 Rxc2
42.Re5 h2
43.Re8+ Kg7
44.Nh3 h1=Q+
0-1