My iPhone is exactly the same. I've had her since August 2007, and, save for a few nicks and scratches, shes still doing her job perfectly. I'm pretty sure I've dropped her AT LEAST ten times, at least three of those on asphalt, the others on tile.
The funny thing is that every time I drop it, I think in my head "Greeeeat... the next time I drop it, it's going to shatter." And then the next time I drop it, my life flashes before my eyes, and time slows as the phone falls in slow motion. Then I pick her up, and she's fine. I applaud Apple for the strength of the iPhone (the first gen, at least).