This chapter is where Rowling starts really building her world. To this point, we've been in reasonably familiar locations, but we're about to fully immerse ourselves in the magical world, so that's what I'll be focusing on in this post, the differences and similarities between the wizarding world and ours. Who's excited? I know I am!
While it's been alluded to in previous chapters, we find out a little bit more about Owl Post. It turns out owls don't just deliver mail, but newspapers as well. We find out that they know when they need to be paid and how to go about making sure they don't get stiffed and at the end of the chapter we find out that owls can find the person they're supposed to deliver to with nothing more than a name. Basically, owls are pretty dang smart it turns out!
Hagrid tells Harry he flew to the island and Harry is certainly interested in the idea of flying. Now, exactly how Hagrid flew there is a mystery as we later find the wizards generally need a broom or some other enchanted item or magical creature to fly (unless you're Voldemort or Snape) and Hagrid in particular has to stick to Sirius' motorcycle. Now, if Hagrid used Sirius' motorcycle, how does he get it back? After he leaves Harry at the train, does he take the boat back over to the island and then take the motorcycle back? That would help explain how the Dursleys get back I suppose, but it seems like an awful lot of trouble.
It also turns out that wizards have their own form of government, the Ministry of Magic, who's main job, according to Hagrid, is to "keep it from Muggles that there's still witches an' wizards up an' down the country". This is really a simplified version of what the Ministry does and it's unclear as to whether Hagrid is trying to make it easy for the barely 11-year-old Harry to understand, or if that's what Hagrid thinks the Ministry does. We'll be getting more into the Ministry when we get to the later books.
The first place Harry and Hagrid go upon reaching Diagon Alley is Gringotts Wizard Bank, and its rife with important moments. We're told multiple times, in prose and in verse, that Gringotts would be impossible to rob, so that when later in the book we find that someone tried to do so that same day, we're duly impressed at the thief's daring. Brilliantly, Rowling lets us think she's played out the Gringotts angle, only to bring its impregnable qualities back to the forefront in
Deathly Hallows. We also meet Griphook, and while it should be a rather glaring clue that he's the only Goblin that gets a name, I'll admit to being surprised when he turned up again later in the series. Gringotts also lets us learn that Hagrid wants a dragon, which becomes important soon, and we learn a bit about wizarding currency (and Rowling's apathy toward good math, 17 sickles to a galleon and 29 knuts to a sickle?! that's one messed up base scale! Not to mention, it really bugs me that earlier in the chapter a woman is complaining about the price of Dragon Livers at 17 sickles an ounce, THAT'S A GALLEON! No one prices something at 100 cents, it's a dollar!) Okay, so that's off my chest, moving on.
Next up Harry meets a boy we'll later learn is Draco Malfoy and discovers that there are unpleasant wizards just like Muggles. He also hears fun new words like "Quiddich", "Slytherin" and "Hufflepuff". Though he does ask Hagrid about them, we'll have to wait a bit longer to get much more than Quiddich is a sport and the other two are houses at Hogwarts.

Last thing Harry does is get his wand. He meets Mr. Ollivander, who it turns out is a pivotal character at the end of the series and learns that the "wand chooses the wizard" which may just be important as well. While all this set up is all very well and good, what I love about this chapter is finding out about people's wands. We hear that Lily's wand was made of willow and good for charms work (I don't have anything interesting about that) and that James' wand was mahogany and good for transfiguration (we know James was pretty good at Transfiguration, considering he and his buddies figured out how to become an animagus quite young, a truly tricky bit of Transfiguration). Hagrid's wand was oak, which we know are strong and tall, but it's Voldemort's that the most interesting, his wand was made of yew, a tree often found in graveyards, pretty ironic for a "man" who's greatest fear is death. The core of Voldemort's wand comes from Dumbledore's pet phoenix, Fawkes, which is interesting to consider as well. Then of course we find out that the wand Harry ends up with is Voldemort's wand's brother, I'm not going to talk about that right now though, because I'm pretty sure that comes up later.
Yep, pretty good chapter it turns out. On the surface its full of interesting tidbits and straight up fun (I really wish my banks vaults were a cart ride away), but when you look deeper, you find oodles of interesting clues about what's to come. What are some of your favorite places in Diagon Alley? Did I miss any big clues?