There have been lots of questions about the Harry Potter blocks. So here's more information.
The block patterns are designed by Jennifer Ofenstein who has made a full Harry Potter quilt. They are available here for free. There is a LJ community that is testing the patterns. They are 5" blockas and are all paper pieced. Jennifer has just added a video of how this done to the pattern page if you're not familiar with it. It's the same method I used to make these blocks and these.
Here's my latest block.