Feeling a bit smug today: I've just been invited back to speak at the Edinburgh International Book Festival this year. I've been a couple of times before and loved it. Edinburgh's an attractive and manageable city and the book festival is just one part of the much wider Edinburgh Festival which ensures there's something of interest going on day and night.
As an invited author you get to pontificate on just about anything you like to an enthusiastic audience (mostly kids, in my case) then sign copies of your books for readers and collectors. My agent advised me years ago to sign books on every possible occasion, since once you do, nobody can send them back.
I'll let you know more details when the programme solidifies.