I watched The Spiderwick Chronicles today. And while the movie was pretty good, I was most impressed by actor Freddie Highmore who played the twins Jared and Simon. (Sarah Bolger, who played their sister Mallory was also pretty good).
Highmore's done a lot of other cool stuff as well. For example, he played Charlie in Charlie and the Chocolate Factory and was the voice of Pantalaimon in The Golden Compass. He'll also be doing the voice for Astro Boy (slated for a 2009 release).