Good to see some nice little activity going on this thread. Posting an old puzzle asked during HP interviews. Those who are already familiar with it kindly let others answer.

Bob and Dave sit down to eat some bread. Bob has 3 loaves and Dave has 5 loaves. A stranger comes up to them and says that he will pay them if he can share their bread because he is very hungry. They all share the bread equally, and the stranger is very thankful. He says that he has eight coins of equal value to divide between the two men, but he does not know how to divide them. Bob suggests that he and Dave split the reward equally, with each receiving four coins. Dave disagrees, arguing that the 8 loaves be valued one coin each. Dave insists that since he contributed 5 loaves, it’s fair that he get five coins while Bob get three coins. What is the fairest solution to this problem?

Today's Puzzle                          
Your job is bowling ball tester. You have two identical bowling balls. Given a 100-story building, your challenge is to figure out from which floor a dropped bowling ball will shatter on the ground. You know nothing about the durability of the bowling balls; they may be very fragile and shatter when dropped from the first floor, or they may be so tough that they shatter from a drop from the onehundredth floor only. This is a bowling ball stress test. What is the most efficient way to determine the floor from which a dropped bowling ball will shatter? In other words, what is the minimum number of bowling ball drops you need to guarantee you can identify the floor from which they will surely shatter? You are allowed to destroy both bowling balls in the tests, provided that in doing so you uniquely identify the correct floor.         

A difficult one...lets see who solves that