I don't know that I'd say anything like "You have nice eyes" to another woman. To me, it wouldn't seem right.
Now, I'll think lots of things. And I have a remarkably awesome girlfriend who is perfectly fine with me noticing other people, and doesn't mind when I say something like "Our new office manager 'Kate' is very attractive," or "Man, I wish 'Karen' hadn't stopped working at the leasing office, she was hot." She doesn't care when I say stuff like that because she knows that she's the only person I look at in anything more than an appreciative glance. However, I don't think she'd be thrilled if I were to tell these other women what I thought -- I think it would be very awkward.
I think it's the conscious decision to act on it. Here is a very attractive woman, not my girlfriend, and I am in her company. No problem. When I make the conscious decision to do something about said attractiveness, I have to wonder why I'd do it. It does not help that I am not exactly a master wordsmith, and it would probably come across as a come-on of some kind, when it's not intended as such. Smooth operator, I am not.
So in short, no, I don't think I would, and if I did, I'd probably feel a twinge of guilt, warranted or not. That's just me, though.
-Matt