I like to think that were I a girl and I caught someone checking me out I'd smile and maybe go talk to him/her when I got a chance.
To me it's generally nice to feel admired. When I was playing Four Square with friends today one girl told me she loved my name and that I looked like I could play a great King Leonidas. Another said she couldn't concentrate on the game when I was playing because my eyes were so beautiful (yes I got the hint and now have her #), then she kept wanting hugs and for me to spin her around
When I look at women it's usually more out of admiration/curiosity than a need to possess them. Even when sexual feeling is there, it's fine. Most guys aren't about to force themselves on you, no matter what you wear.
Also I second Erki, hugs are great.