A good place to find icons for clickable events, or small decorative images. Just a search for the word "bird" turns up five pages of material.
Another good place to find icons. You'll see some overlap with Icon Finder, but don't be fooled...this place has plenty of items not available there.
One more place to download icons and simple illustrations.
Iconbug has the distinction of having a pretty fast search engine, compared to some of the alternatives.
Free Icons Web is probably the least consistent in terms of speed, but it remains one of my favorite places to check for images.