I strongly disagree with b's assessment of the Lepanto. I have been very successful with Italy playing the Lepanto (and not Key version either):
http://webdiplomacy.net/board.php?
gameID=13087#gamePanel
That's my Master's win with Italy going into the Lepanto.
In order to be successful with the Lepanto, you have to have a friendly Austria (which isn't terribly hard to get) and focus on Turkey. In addition, the Lepanto does *not* have to convoy the army to Syria. Italy can out-muscle Turkey in the southern sea zones with Austrian help. In addition, your first gains can come at Greece or Bulgaria and after Turkey loses its first center, then it's downhill from there. Your goal is to get Italy and Austria to take on Russia and Turkey. Since you are 100% focused on Turkey and Austria is split 50/50 or even 60/40 with some measure of focus at Turkey, then you're golden. If you ensure Austria keeps busy while you're picking apart Turkey, your job is simple.
In addition, as long as you keep good communication with Russia while you're taking down Turkey, you have an ally to fight against Austria if you want the stab. If not, then you simply talk your Austrian ally to focus east against big Purple while you either go west or take the stab for convenience.
Those that continually attack Austria at the outset as Italy will eventually find a game in which they are eliminated by a Juggernaut or powerful Turkey. Plain and simple.