What does holding up index and little finger mean?

Index and pinkie finger alone means "giving the horns". This is very popular in the Italian culture and one would do it for several reasons.

1) Someone wishes evil upon you, and you counter with "the horns".

2) You would give the horns to someone as a way to insult them by saying they are "Cornuto" (have horns). "Cornuto" in Italian is a person that is being cheated on by a spouse or girlfriend. This insult is very popular to be said to Italian soccer referees. "Arbitro cornuto!!!"

The you have index, pinkie, and thumb, that means "Love". Very popular in 80's rock bands.