Here are 25 of the most beautiful (and free) PSDs filled with great user interface elements that we could find.
Some are full kits and some are just a couple of elements. Use and enjoy them and go create something useful and beautiful.
If you would like to search for some other beautiful and free user interface PSDs the 2 best sites I have found are 365 PSD and Icon Deposit. You can also find some on Dribbble, Design Kindle and Premium Pixels. If you know of others, please let us know!
Hanna UI Kit
Black and Pink UI Resource
Grayness UI Kit
Smooth UI Kit Monochrome
Poky UI Kit
Cloudy UI Kit
Piotr UI Kit
Clean Blue UI Elements
Yogurt UI Kit
Heavenly Assorted UI Kit
iTunes Inspired UI Kit
Modern UI Kit
Creamy UI Kit
Detailed UI Kit
UI Bundle
Vector UI Kit
Clean UI Kit
Simple UI Kit
Vector UI Bundle
Smooth UI Kit
Fresh UI Kit
Light Button UI Kit
Light User Interface
Pixel UI Kit
Simple UI Elements
If any of the links to the above PSDs are not working please let us know.