Muscle Group: Shoulders
If you place the bench so that it inclines every so slightly, you will be able to lean back and press more weight than you are normally used to. This will hit your fast twitch muscle fibres that much harder, stimulating major growth in the front and side deltoids!
Sit back on an extremely high incline bench, as high an incline as is possible without the seat being upright, and take a dumbbell in each hand at shoulder height, elbows out to the sides and with your palms facing forward.
Press the weights straight up until they touch At the top, then lower them again to the starting position and feel a great stretch in your shoulders.