Your survival gear should reflect the situations you will encounter. I would grant that cash works well in urban situations. In a wilderness setting, however, cash is just tinder (not legal tender)for starting a fire. Does anyone know which of the denominations burns best? Does a Franklin burn hotter than a Lincoln? I am not aware of any studies in this area....

Caution....Cash should not be used as a wound dressing. The bacteria count is way too high. If you have a silver dollar, it might be used as a signal mirror, but it won't be all that effective.