It's not terribly popular, but there's a very good way to decline the From Gambit: 3 Nf3 dxe5 4 e4, resulting in positions that resemble the King's Gambit Declined.
See http://www.oocities.com/drawyah/ for more theory than you can ever use on this line.
Here's a couple From Gambit games I played with a friend of mine. He's a real gambiteer, and playing him is always fun even when I lose. I'm also terrible at open positions, so I often blunder the game away. Not this time though! I won both of these! He had black in both.
The 2nd one I think I REALLY should have lost it.
I'm still a beginner and I really have no idea how to play against the From. All this was by ear.