What does it mean when a girl looks at you from the corner of her eye?

Ah. Well, this is usually the beginning of her taking an interest in you. Look at her closely, are her pupils dialated while looking at you? if so and she holds her stare for a long time or really quick and looks away she likes you. The next stages of this will be her flirting with you. She may call you stupid for a comeback when you have set yourself up for it, or if you pass each other in the hallway she may stand close to you. There are numerous ways to tell... but this means she likes you.