Aldran wrote:
I believe, directly, its short for something like "You can search me for an answer, but if I had one Id have told you already" or something to that effect.
I believe it came from England initially, and IIRC the term was used moderately frequently in the Sherlock Holmes books, but /shrug, this sentence is generated from my memory, and is subject to being entirely wrong, feel free to do your own research.
Aldran
I don't know where it came from, but it was common in the US in the 70s. Rowling probably heard it a lot as a girl, and it's not such a common slang term now. Remember the author isn't the same age as the readers.
When people said "search me," when I was a kid, there was a slight emphasis on "me" - usually accompanied with a shrug. You may have heard "beats me" or "you've got me" but not "search me" at some time. But it's as simple as "I dunno (shrug)."
I don't think the wizard crackers were in the movie. And there are some things that never get explained in the book or the movies. As someone who used to try to write fiction my guess is that they were explained in early drafts but got edited out to shorten the length and as not really necessary to move the story forward.
I personally think changing the title from Philosopher's Stone to Sorcerer's Stone was idiotic. It changes the meaning of the title. Nicolas Flamel was an historical figure, an alchemist, and the proper name for such a stone would be philosopher's stone. If they were going to leave Flamel in at all, why change the name of the stone? I hate Americanizing and dumbing down.