Touching his hair

In the wild, birds preen to maintain their feathers and look their best for potential mates.  Similarly, a guy aiming to look his best for you, will voluntarily or involuntarily dip his heads forward and gently cup his hair.  A guy who does this as he is approaching you or vice versa, is likely a little nervous about his appearance.  The manner in which he runs his hand through his hair depends largely on his hairstyle and what he thinks will make him look most attractive.  You'd be surprised how often guys do this.  Next time you excuse yourself to visit the restroom, glance back.  There's a very good chance his hand will come into contact with his hair.

Touching his face

If a guy starts to touch his ears, rub his chin, or stroke his cheek up and down with back of his fingers, there's a good chance he's attracted to you.  It's a combination of preening and nervous excitement.  A guy tends to self-stroke when he badly wants to stroke the person in front of him, but doesn't feel like he can just yet. 

Licking his lips

A guy may consciously or unconsciously lick his lips in anticipation of coming into contact with someone he is attracted to.  When your eyes meet, automatically his lips will part, if only for a brief moment.  The anticipation of coming into close contact with you will likely make him nervous and put butterflies in his stomach.  This uneasiness will typically inhibit the flow of secretions from his saliva glads, causing his mouth to get dry, ultimately leading him to lick his lips. 

Hand gestures

Open palms signal openness and honesty.  Men who talk with their hands are typically above average communicators.  The wider the gestures, the more likely he is attracted to you.