The folks over at the Presetting Lightroom Flickr group have compiled a collection of 180+ Free Lightroom Presets with sample before and after images for anyone who’s interested. Included in the collection of links are Wonderland Lightroom Presets and Presets Heaven.
Pro Photography Show has a similarly expansive collection of links to free Lightroom presets. Collections range from authors Sean McCormack, Jack Davis, and Matt Kloskowski to Adobe’s Exchange community.