If they're not being rude whatsoever, I take it as a compliment and usually just smile. With people that I feel might do or say something, sometimes I just move my hand around so that my wedding ring is clearly visible. It doesn't offend me though, and I enjoy checking out men and women alike - sometimes Zac and I do it while we're sitting somewhere in public, just enjoying watching the people go by and talking about what we found attractive on them =P
Don't recall ever catching anyone in the act. Think woman are more tactful than men. If I did though I wouldn't be offended. It would be flattering I think.
Annoyed / Disgusted if it's someone I'm not familiar with.
Ooooh. Another point I didn't think to make. When I walk around with my best female friend, she knows that I like to make people feel good because a compliment could totally change someone's day. So if I see someone who I think is cute, I'll smile at him, and when we walk by I'll say to her, "Oh he's cute!" so he can hear. I've seen big smiles from that and it makes me happy. Zac knows I do that and he's fine with it - he actually likes that I make people feel good. I don't go up to people and flirt though.
I like it! It's flattering as long as its not over the top but the odd cheeky smile is always nice. Drunk gropey girls can get boring quick mind you...
Okay. Just out of curiosity, and I'm not judging you one way or the other, if you're never gonna see these people again, what specifically irritates you about it?
Living in Chicago, taking public transportation, as a female, if a dude is checking you out, he's not looking at your eyes, your hair, your smile. He's not admiring you as a beautiful thing, he's taking a mental image to fap to later. At least, by the way most guys look at you, that's the way it feels. You get your creeps, your froddeurists. I have even had a guy whip out his dick on the train and start jacking off right there at 11am on a Monday morning. Definitely didn't take that as a compliment.
Whether I'll see them again or not, still kinda grosses me out.
Although, I may have interpreted the OP wrong. Based on prior experiences, I took "checking out" to mean "leering", but upon further thought, there is a difference and I think as long as a guy wasn't being a creep about it, I might not be bothered.
I noticed that females that are used to guys looking at them won't be grossed out if the guy is hot.
Living in Chicago, taking public transportation, as a female, if a dude is checking you out, he's not looking at your eyes, your hair, your smile. He's not admiring you as a beautiful thing, he's taking a mental image to fap to later. At least, by the way most guys look at you, that's the way it feels. You get your creeps, your froddeurists. I have even had a guy whip out his dick on the train and start jacking off right there at 11am on a Monday morning. Definitely didn't take that as a compliment.
Whether I'll see them again or not, still kinda grosses me out.
Although, I may have interpreted the OP wrong. Based on prior experiences, I took "checking out" to mean "leering", but upon further thought, there is a difference and I think as long as a guy wasn't being a creep about it, I might not be bothered.
Also, in an urban environment, I know that guys are not typically thinking, "Wow, she's really pretty!" They're thinking more along the lines of, "Dat ass!" Thinking about the city is specifically why I broached this topic. I'm in the city a lot, and I usually see a lot of beautiful women when I work. My coworkers do not typically hide when they're looking. I'm not saying I DON'T look, but I try not to appear like I'm staring, like a hungry zombie. I steal glances. It just seems more tactful.I love it! Usually I react by giving eye contact or a smile. When it's a guy checking me out its a lot more awkward though. I usually look away.

I'm terrible at knowing when I being checked out. My female friends generally have to tell me when these things are happening.
*sigh* This is why I'm still single... *sniff*