|Snippet from the Perqui iconset|
My favorite is Icon Finder, which offers a great search with icon previews and designers can upload multiple icon resolutions. Most of the icons are released under some Creative Commons license, which is great for both the designer and people like us. Linking back is a great way of promoting a designer and seeing some great icon could even lead to developers contacting designer to start working together :D
In addition, Icon Finder recently started a Marketplace which even allows designers to directly sell their works instead of implementing their own web shop.
Another great resource is Icon Archive, which is pretty similar to Icon Finder, but the website is not as pretty and usable. The icons hosted there are also not as good as on Icon Finder.
One of the disadvantages of Icon Finder and Archive is, that the icons are usually available as PNGs and ICOs (rarely as SVG). Even though they often available in multiple resolutions, you sometimes need them in an even different resolution because you want to combine them.
This is where the third great resource, OpenClipArt Library, can help you. It's a great place to get vector graphics (SVG), which you can freely reuse for your own good. And the best about OpenClipArt is the license: Public Domain! That's why I started working with Inkscape to design my own icons using parts of really great graphics available on OpenClipArt.
Do you have some other locations you get your icon inspiration from? Would love how other not so experienced programmer-designers do it – except for actually having a designer as a partner ;)