几个免费的、资源丰富的图片、图标、矢量图、声音资源网站
Office Online Clipart by Microsoft
You can get more than 150,000 free images and sounds from there.
Illustrator Exchange by Adobe(Illustrator)
Not only images and sounds resource,you also can download hundreds of easy-to-install extensions, time-saving functions, code and more. 
Vector Cliparts by Ndesign Studio
These graphics are in .pdf format, support most graphic application like Flash, Photoshop, Illustrator, etc. These cliparts/icons are great for creating webpage link buttons, forum icons, or software interface.
BittBox privdes homemade vector freebies, design tips, tutorials and bitts, include Photoshop/Illustrator brushs, Metal/Glass Button, Glass Header, Glass Orb, Glass Badge, Glass Bar, Glass Arrow Button, Butterflies and more
Free Vector Cliparts by Clipart deSIGN
Free Vector Clipart, Ornaments and Icons section and currently it offers over 500 free vector images!
You can find all the flags of the world at there.
Free Photoshop brushes and audio samples for deejays.
You can find soooooooo many high quality categorized collection of desktop icon sets.In total over 16,400 quality icons for Windows (XP, Vista, etc.), Macintosh (OSX, OS) and Linux Systems (PNG Files) in 593 sets from 145 icon authors.
