I can see that a good player could take advantage of it. It feels like I leave my king wide open.  I'm guessing I should castle long when I do this?

Augh!  We answered at the same time!

That is called the Four Pawns Attack in the King's Indian Defense.  It is very agressive.  If Black doesn't counterattack swiftly, he will get bowled over like I saw in that game.  If he plays well, White's pawns may become overextended and be targets later.

This is a line in the King's Indian Defense, obviously called the Four Pawns attack.  I don't think it's played as often as the Classical or Samisch lines.