For Harry Potter fans

Wow, the Florida lottery is up to 10.6 million Galleons (that's $6 million for Muggles).

A Sickle is basically the same as a quarter, and a Knut is more or less a cent. A Galleon's a little harder to work with, but it's around $4.50, so you can use $5 for rough calculations and then knock 10% off the final figure.

Convert Muggle money and wizarding money at HogwartsAlumni.com.

For word fans and etymologists...

This is a site I would have had to create if it didn't already exist -- an etymological encyclopedia of JK Rowling's wizarding words. Just about every made-up word and name from the books appears there with an explanation. For example:

Dumbledore, Albus - Headmaster at Hogwarts.

"Albus" means "white" in Latin. I assume this is so because he's sort-of the leader of the "light" side. Go figure.
"Dumbledore" is an English word for "bumblebee". J.K. Rowling says that it "seemed to suit the headmaster, because one of his passions is music and I imagined him walking around humming to himself."