If it's just randomly on the street, then I usually just admire them. Pretty things are nice and pretty women are nice to look at :)
If it's in a bar, then what I think will depend on what she's doing. If she's skanking it up by drunkenly dancing on top of a table then obviuosly I'm going to think much worse of her than if she was just hanging out with a bunch of friends.
Do I get jealous? Not unless I'm there with my guy and he's paying her too much attention. Otherwise no because there's no reason to be jealous if he doesn't give a crap about that girl.
Do I compare myself to them? hmm sometimes I might think 'oh I wish I had her boobs' or 'omg I love her hair' but that does not mean that I also start thinking 'ugh my t*ts are so small I hate them' or 'damn I'm ugly.'
There's always going to be someone better looking than you in this world so there really isn't any point to get mad or stressed out about it.
lol I don't get jealous at all...instead I think "wow, she's pretty/hot" its all about being comfortable with who you are and how you look...if your're not then that's when jealousy rears its ugly head.
Actually, I've got pretty good self-esteem, so my usual thought is ,"Look how cute she is! I like her: fill in the blank (eyes, butt, hair, style, whatever it is)."
I stopped being jealous of other women a long, long time ago. After all, you can't be the best at everything, or hottest, or whatever. Life just doesn't work that way.
Jealousy never harms the person it's aimed at; it only hurts the person who is jealous. You're better off learning to love yourself and all of the wonderful attributes you DO possess. Besides, life is too dang short to get caught up in all the nuttiness.
I get jealous, depressed sometimes. I'm not ugly, but I have more than my fair share of flaws and when I see someone without my flaws, and even with no flaws at all I get sad, she must be happy. I feel inferior, and I know I am, she has it made. Society bases allot of value on a women's looks, people are lying to themselves when they try to say otherwise.
I find myself hot, I am not jealous, I know that ideal girls not exist. if I see she has nice hair, dress.. anything then I think if I could have such too, I look for tips for me. If I am with my boyfriend and is any hot girl he looks then I try to wear so that other boys look at me and it drives him crazy hehe