Iconza — collection of 112 customizable free icons that can be colored and reduced in size to your taste with the help of a web-based application.

The set currently contains 112 totally free icons. You can choose any color, size 16x16px, 24x24px or 32x32px for the icons. Whole set – PNG files – can be downloaded as a ZIP file.

Project Icon Set – contains 18 beautiful & free icons related to project management.

The set includes the icons address card, bar graph, calendar, clock / time, conference device, contact, documents, draft, mail, marker, milestone, notes, portfolio, project plan / gant chart, search / find, sitemap / flowchart, todo and user / resource.

Web Injection – Free Icon Set for webmasters and web developers.

The set includes 26 free icons at 48×48px size and in a Png format. This Free Icon Set is for use in your personal and commercial projects, and can be used without attribution.

Easter Bunny Icons – icon set include 44 cute and Free Easter Bunny Icons that you can use for web and print design.

The icons are available in vector PDF format, meaning you can resize them to any size to fit your design.

Icons include: bunnies, birdies, Easter eggs, and candy bars. You can use them to spirit up your blog themes or to design your Easter postcards and invitations.  You can also combine them or add custom messages to the signs to create your own icons.

Be sure to check out IconDock Free Icons section for more Free Icon Sets.

WooThemes Icon Set – The free download contains all 79 icons, sized at 256×256 pixels and available in both PNG and GIF formats.

As an added bonus to WooThemes users, they will also be able to download Illustrator source file, which will give them high-resolution, vector copies of the icons.

Free to use in both personal and commercial projects.