Kansas and Other Dramatic Finishes

Well, as everyone probably knows by now, the Kansas Jayhawks won the NCAA men's basketball championship last night in dramatic fashion. Mario Chalmers hit a game tying 3-pointer with 2 seconds left in regulation to send the game to overtime, where Kansas proceeded to dominate Memphis and win by seven. But that was not the only drama last night. I'm not sure if this was a normal night for baseball, but in addition to the Kansas last second shot, there were several late inning heroics in MLB last night too:

1. The Angels beat the Indians with a walkoff grand slam in the bottom of the ninth inning by Torii Hunter.
2. The Astros beat the Cardinals with a walkoff two-run homer in the bottom of the ninth inning by Miguel Tejada.
3. The Rockies beat the Braves with a two-run homer in the bottom of the eighth inning by Matt Holliday.
4. The Orioles beat the Mariners with a solo homer in the bottom of the eighth inning by Aubrey Huff.

That seems pretty unusual to me - four games that were won with home runs in the home team's last at bat. I'm too lazy to do the research. Can anyone tell me if this is something that happens frequently? Anyone?