This is one time when I wished Blogger had a feature like the LJ cut. So I hope this will suffice:
I first noticed this on The Leaky Cauldron a couple of days ago. Rising Sun Productions is an Australian company specialising in providing video effects and animation for films around the world.
One of their projects is connected to the Harry Potter series. They did some extensive work with Half-Blood Prince.
Have a look at at their work here. It's just amazing how they were able to blend live action and special effects to give you the finished product.
Some of what they've shown include Dumbledore's hand, Slughorn's transformation from plush comfy chair to human, Weasleys' Wizarding Wheezes, the Sectumsempra scene, and Snape's fight with Harry.