Oh, Say, What is Truth?

Today I watched the DVD by Rhonda Byrne entitled "The Secret" with some friends.  I had watched parts of it at my sister's house a few weeks previously and--for the most part--I loved it.  I thought it taught a true and potentially life-changing principle. I recommend it to everyone.  There were a few things that I thought were a little over the top, true, and some of the examples as to how you could use "the secret" were downright selfish... but to me, I was looking for the truth in it all, and I thought there was plenty to be found.  I think that is true to a lot of things.  For those of you who know about the movie or book, what are your thoughts?  Truth or Hoax?  For everyone, what constitutes truth?  And what level of purity is demanded in said truth?  If you have to peel away things that are misleading to get to the truth, is really something good--or should it be avoided because of the potential to lead people astray?