NAPP is the national organization for Photoshop users. The acronym stands for National Association of Photoshop Professionals. It was founded by editor and publisher Scott Kelby to organize and provide training and other resources for users of Adobe Photoshop.
Founded in 1998, NAPP grew from the requests made by students who attended the Adobe Photoshop Seminar Tour which provided training for Photoshop. There was a need for a centralized area for continuing education, as well as a repository for support and guidance. Beginning with a few thousand members, it now boasts over 75,000 members in 107 countries around the world. There is even a twice annual Photoshop World where Photoshop users gather to learn and share.
Along with membership, you also get the monthly Photoshop User Magazine which contains the latest information, tutorials, and product reviews on Photoshop-related gear. They have now expanded to Photoshop podcasts and Photoshop TV that features, along with the editor, Matt Kloskowski, Dave Cross, Corey Barker, and Rafael "RC" Concepcion.