What does it mean when a girl keeps staring at you

Does she want me to make a first move? Does she really like me?

I'd say you either have something on your face or in your teeth, or she thinks you're cute.
I'd say go for it *shrug*

At least, if I were to stare at a guy it would be because he's good-looking.

I was on a train back home (which involved changing trains 3 times in 2 hours). I was walking towards the train door; then a nice, around-5-feet-4-inches girl with blonde hair pressed the button and opened the door for me when I was still quite far. I said 'thank you' and she smiled back. I changed train and found her waiting for the same train. We were sitting not too far away from each other facing opposite to each other. We looked at each other several times. Really wish the train was a bit more crowded then I could have a better 'excuse' of sitting right opposite/next to her.

I'd say it doesn't matter whether she stares at you or not. If you find a girl attractive and you wanna get to know her better then go talk to her, ask her to go to the movies with you, do something.

Afraid of rejection? So what? Rejection lasts seconds. At least you won't be living your whole life wondering "What if".

eye contact is everything!
you'll know when it's more than just a glance because she'll do it more than once, and the stare will usually follow by a smile. but i've noticed when the girl smiles, she will normally look to the floor.

easier said than done, but take a chance cause life really is too short

Make a move and find out. If she rejects you at least she will have more respect for you now than if you haven't had the guts to make an approach at all.

hm.. I think it applies to if you know the girl, and if, how long? if she is a stranger? etc.

When I am starring at a guy, it is most because of my opinion that he is sweet

why can't gal just go and talk to the guy instead of staring ? will it make life easier?? LOL

because girls are more shy than boys and boys should do the first step?