Melt chocolate and margarine in microwave on med. for 1 min., stir, and put back in if needed--until chocolate is smooth.
Heat water until it starts to boil; stir in coffee.
Add coffee mixture to chocolate.
Refrigerate 1 hour.
Form chocolate into walnut-sized balls and roll in the chopped hazelnuts.
For orange or strawberry truffles:
Do everything the same, except leave out the coffee and water and add 1/2 tablespoon of either orange or strawberry extract and roll into cocoa or powdered sugar. (you could even add some red powder coloring to the powdered sugar for Valentine's Day!) :)