Question: I was told by a friend that star notes were worth more money than the number that is printed on the bill. I have found a few of them, is there any truth to this?

Answer: I'm not a currency expert, but I had the same question when I came
upon one as a child. The research I did back then indicated that they are replacements for a note that was damaged during its creation. They are generally common enough that they won't command much (if any) of a premium unless you have a sequential series of them. For more information about them, see this HowStuffWorks entry.