The Harry Potter Trail tour is a somewhat less formal tour you can do in Scotland to learn a bit more about the area in which J.K. Rowling spent time writing the Harry Potter book and some of the possible influences the local area had on the Harry Potter Universe. The tour itself is free and from the beginning it is made clear that much of what is shared is speculation, although some facts are thrown in. At no point did I feel the tour guide was being malicious in his intent. He made it clear that not everything to be said has been confirmed by the author.
That's our tour guide in the picture above. He had a great sense of humor and it mixed in well with the tour. We walked around several blocks of Edinburgh's Old Town, which in itself was quite interesting. I do know he shared several correct facts as these were facts I'd previously heard from J.K. Rowling herself (in interviews, not in person sadly). He did a great job answering questions and throwing out trivia questions. The trivia questions were beyond me but they were always answered by someone in our group correctly.
The tour itself is free but there is a push for donations at the end. I thought the tour was well worth our time to provide a donation to the guide. At the end of the tour you are taken down an alley which could have served as an influence on Diagon Alley in the books. It had that look and feel to it. The alley also had a store selling Harry Potter memorabilia that we checked out the next day. My 6 year old LOVED this store and picked up a Harry Potter journal book.
If you're a big Harry Potter fan and are looking for a low-cost (donation only) tour, then you can't go wrong with this Harry Potter Trail tour.