Gustavo Pimenta is a user experience designer focused on making the Web a better place. He mentioned that he is addicted to making screenshots of some of the best design elements / soultions, e.g. 404 Page, Autocomplete, buttons, breadcrumbs, comments, forms, graphs, headings and a lot more. I am sure this hugh collection of really nice design elements / solutions can give you so much inspiration for your web / web application design.
Source: Flickr: Gustavo Pimenta’s Collection: [Design Solutions]