Well, Sessler, here's a little something I picked up. Blaise Zabini is mentioned during the sorting in Philosopher's Stone. And, except for that one sentence, his character is not mentioned again until Half-Blood Prince. Just something I noticed when re-reading the first book. I like how Rowling introduces characters, and you don't even know she's doing it, and who might not even do anything for several books. And it doesn't take away from the current story, because it's so off-hand, you don't even realize it until the second time you read. Plus, it shows that she really knows what she's doing and has a lot of the characters and situations in her head from the beginning.