They're everywhere pretty much. There are usually characters out at the front of the Parks, so it's handy to have one with you when you get there. You can get them at your resort if you're onsite. I use books that I get at local craft stores, that are a little bigger and have a spiral binding -- easier to handle for my DGS and the characters (we can fold it back to the page we want signed, and then add the photos when we get home). I put velcro on the front of the book, and on the pen (loop on the pen; hook on the book, so nothing sticks to the character) -- so we don't have to search for the pen.