Body Language! What is good body language and what is bad body language?

Each person has different signals (some are more outgoing than others) but there are many indicators of interest. If she keeps up eye contact and seems comfortable and relaxed she is most likely interested versus arms crossed and rigid stature or constantly looking elsewhere as if she is looking for an escape.

Other positive signs: playing with hair or other objects, licking her lips, laughing at your jokes, a slight tilt of her head, compliments especially those tailored to you rather than more basic impersonal ones (I like your style vs. I like the way that shirt fits you)

Negative signs: inability to keep eye contact, turning her back on you, tuning out of the conversation, short abrupt answers to questions (yes and no rather than longer answers), not participating as enthusiastically in the conversation, shielding her body from you

Some of those are not as much body language but show interest/disinterest all the same. As you said physical contact is definitely a huge part of it. Small things like a touch on the arm or shoulder go a long way.

Voluntary physical contact is DEFINITELY a big one, especially if it is repeated. You're right, I'm not going to be touching a guy I'm not into except on rare occasions. Smiling is also good. If she smiles a lot when you talk to her or when you make eye contact, that's a good sign.

The big thing is open versus closed posture. If a girl closes up, for example, crossing her arms over her chest or sort of scrunching up, she's uncomfortable and probably wants to get away. If she's got a more open stance that doesn't hide her chest, again, good sign. Also, watch to see if she mimics small changes that you make in your posture. You lean forward, she leans forward. You put your elbow on the table, she puts her elbow on the table, stuff like that. That's a key nonverbal flirting technique.

It's all in the eyes. Otherwise MissDemeanor pretty much summed it up nicely.

Pay close attention to her pupils. When you first start talking to her look and see how big they are and notice the lighting around. As you talk to her keep good eye contact and pay attention to her pupils. If she is real interested then they will be so big that you will hardly be able to see the coloring of her eyes. This has worked very well for me.

Body language that shows that she's interested? She flings her naked body at you and tells you to make sweet passionate love to her.

Just kidding, that never happens in life (unless you pay for it).

If she talks to you more than 2 minutes and doesn't walk/run away, you're good. Smiling, laughing, and touching are also good signs. Trust me, when a girl is into you, you'll know. :)