Many web developers around the world use the Subtle Patterns website when searching for a pattern to use in web projects. The Subtle Patterns team collaborated with the team that brought you CSS Hat, and they created The Subtle Patterns Photoshop Plugin.
The plugin is always synced to the website's vast library of patterns as long as your computer can connect to the internet. The plugin includes a search bar and extremely quick indexing of search results. Fortunately, it also includes real-time updating, so you can preview your changes before committing – especially when using the zoom and opacity features. The plugin is only available via their website and will run you $11.99 (USD).