I'll tell ya right now why the Fried Liver is almost never seen anymore...
Nxd5 lines have become so rare, not because of the Fried Liver but because of Morphy and Fischer's favorite, the Lolli attack.
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6.d4!
This move saves Nxf7 for later, say after exd4 O-O Be7 Nxf7! wins. There is no need to sac the knight right away...black can hold his own in the Fried Liver. In the Lolli though...not really. Masters don't play Nxd5 anymore because of the Lolli, so why not invest some research into it?
Also, one more subtlety I thought I'd bring up...if you dread the Na5 lines like I do, save Ng5 for another move. I prefer 4.d4! and will play a Perreux variation if it doesn't go back into a Lolli. This move order effectively eliminates the Na5 line. E.g., 4.d4 exd4 5.Ng5!
Someone on here posted this site already, but:
http://www.rci.rutgers.edu/~goeller/urusov/perreux/index.html NeX iRae
P.S. Get off Yahoo! That site's worthless...check out USCL, FICS, ICC just to name a few. Yahoo is just filled with cheaters and people who don't know how to play...ugh...