You just click on the little ticky box, and scroll down to the bottom and hit "update wishlist".

When you go to your wishlist, it shows the categories first. You have one category by default, but you can add more.

Is there an easier way to add items to your wishlist besides typing in the name?

ah I was always wondering about that and how seemingly random items would end up in my wishlist. I though it was just part of the hover-over thing.