Each of the contributors to this blog has his or her own list of things they want to accomplish. Rather than thinking of them as lists of things we want to do before we die, we think of them as challenge lists. Each item is something we challenge ourselves to accomplish. Whether that item is learning a new task, conquering one of our fears, or just something we think would be fun to do one day. Our mission can be summed up in one question: Why put off, until tomorrow, what we could do today? We encourage everyone to make their own lists, challenge themselves, and take advantage of every opportunity that today grants us.