Because people have been asking about images as well, here’s a quick list of Navigation and Social Media Icons - image format. Part One:

01. FamFamFam (PNG)
An oldie, but always a popular choice. There are three sets online, including the World Flags which some might be interested in. I would recommend “Silk” as it has more than 700 everyday and popular UI elements icons to choose from. No Social Media Icons.

02. Premium Pixels Icon Set (PNG/CSH/PSD)
As described, 58 pixel icons with a PSD included. No Social Media Icons.

03. 41 Social Media Icons (PNG)
Sqaure set of social media icons in two sizes, includes popular sites like Twitter, Tumblr, Last.FM, Facebook and many more.

04. 106 Pixel Perfect Icons (PNG)
Another pixel icons set. There is a “F” and “T” that refer to Facebook and Twitter but no other Social Media icons.

05. Grunge Minimal Iconset (PNG, Vector)
A gray/transparent circle set of Social Media icons, comes in three sizes and includes the main sites.