It's an old one, but I heard it again today and it's still funny!!!!

A brand new -- and not terribly bright -- freshman co-ed was walking across the college campus and passed a group of older frat boys. One of the boys yelled at her, and said, "Hey, I'll bet you five bucks that you can't climb up this tree!"

Well, she laughed and put down her bag and climbed up the tree and back down. The college boy gave her the five and she giggled and went on her way.

When she got back to her dorm, she told her roommates, who were shocked. "Don't you know that those boys just wanted to look up your skirt and see your panties!"

Well, the next day, the girl was walking across campus AGAIN, and the boys offerred her the same bet AGAIN. She took it, and pocketed another five dollars. She went on back to her dorm room laughing about it, and told her roommates again.

"Didn't you learn anything from yesterday!", they said. "We told you that those boys just wanted to peek at your panties!"

The girl just giggled, "Yeah, but the joke was on them! This time, I was prepared. I wasn't WEARING any panties!!!"