Marieh,
I totally understand where you're coming from and maybe it's a woman thing. I'm not sure if most guys are used to being looked at the way women are often looked at. Sure, it can happen to guys as well, but it doesn't seem as common. If a guy just kind of has a friendly smile and nods to acknowledge your presence, no problem.
If a guy looks at you or watches you--and a woman can tell--and he's making you feel like a steak being handled at the meat counter, yeah, you're bound to feel uncomfortable, embarrassed, and uneasy. A woman can also tell when a man's eyes are stopping at her body parts as well.
I know I find those kinds of looks especially unwanted if the guy is from a different generation as well. I work with a lot of young guys and a 20-year was giving me that "up-and-down body scan" and I was thinking, "For the love of Pete, stop looking at me like that, I could be your mom!!!" And no, I wasn't wearing something "inappropriate". I was wearing our work dress code--khakis and a polo shirt. I have the same feeling about a guy who could be my dad or Grandpa as well.
It all depends. Sometimes, yes, we do misinterpret looks but sometimes... a guy has no business looking the way he's looking. And no, it doesn't make me feel special because I'm being looked at. It makes me feel like an object that he feels free to look at any way he wants, with no respect.
For any man out there who can't relate--think of how you'd feel if another man who lived a homosexual lifestyle was looking at you and "checking you out".
That's what some of us women feel like when guys look at us in certain ways, because sometimes their intentions are obviously not in our best interest.