Transparent Glass UI: Free PSD for User Interface Design
This free user interface pack, brought to you by PixelsDaily, includes a variety of popular elements used in web application and website design. Every element has been carefully handcrafted to maintain consistency and quality. The included PSD file is well organized and ready for customization. Due to the transparency of the UI elements, they are flexible and should work well with any background.
http://sixrevisions.com/freebies/web-page-templates/transparent-glass-ui/