Here is a selection of free high-quality icons that are available use. Don’t forget to read license agreements before using icons in your designs – they can change from time to time.
DDIcons (65 PNG + PSD Icons)
Here it is! My first icon set. I have to say I had a blast doing it. I stopped this set earlier than I tought because I want to start a new one, with more details and precision. Hope you guys like it! 
Freebie: Professional E-Commerce Icons Set (20 Icons)
Today, we are glad to release a set of 20 high quality E-commerce Icons in 64×64px, available in .png-format. This set was designed by Web Icons Set with the purpose to be used in e-commerce websites and has been exclusively released for Smashing Magazine and its readers. The set includes icons such as Empty Basket, Full Basket, Credit Cards, Delivery, Secure Payment, Checklist, Gifts, Shop Open, Shop Closed, Contact, Wallet and others.
200+ Exclusive Free Icons: “Reflection”
Icons are a great and quick way to enhance your projects. They add a certain personality to your designs and make things pop when they need to. Today we release a new set of icons which we call “Reflection”. It’s simple yet elegant and stylish at the same time. You’ll find these icons great to use at small sizes, such as for website navigation, menus and more. Both vector and raster versions are included.
15 shopping icons (Free PSD and PNG)
This shopping icons were drawn in a orange and green hues. The set includes 15 icons among them: tags, sign, shoulders, bags, gift box, bank cards, basket, trolley, delivery truck and more. The unique set of icons will add a bit of style to your project. You can use these icons for your e-commerce website, online store or web applications. The icons were made with vector shapes, so you can scale to any size without loss of resolution. The set is available in PSD and PNG formats. The .PSD file has well hierarchy and is ready to customize. Also you can grab PNG images (128×128 px.) with transparent background for using straight on the web. The files are completely free for both personal and commercial use.
Plastique: Over 400 Icons and counting
Plastique Icons is a set of 434 (and growing) web and application icons inspired by advertising clip art of the 1920′s and 1930′s. The set is available in vector format and also includes a CSS/PNG sprite version.
Map Icons Collection
Map Icons Collection is a set of more than 700 free icons to use as placemarks for your POI (Point of Interests) locations on your maps. You can use them on Google Maps with the “My places / My maps” feature or automatically by using the Google Maps API.
Glyphish
Great icons for great iPhone & iPad applications.
Monochromatic Iconset _1 by ~aipotuDENG
PSD available include layer style and shape layer
Real Estate Icons
This set is the fifth of many free web graphics that we plan to make available to the community.
3D Glossy Icon Set: 20 Free Icons (with PSD)
This free icon set by Iconshock, released exclusively here at Six Revisions, features beautiful, pixel perfect, glossy 3D icons. Each icon comes in 5 sizes (PNG format), with Photoshop PSD files in case you would like to tweak the icons.
Mini Designer Icon Set – 10 Free Icons
This set of icons was designed with designers in mind, there should be at least one thing in here that speaks to any designer, whether it’s your love for a certain graphics software package, your obsession with Apple iGoodies, technical drawing, photography or sketching ideas in your moleskine notepad, we’ve got you covered.
28 Toolbar Icons (PSD included)
To continue our grateful thanks to our readers and community in general, we are glad to release yet another free quality icon pack: 28 toolbar icons. These icons come in PNG format in 2 different sizes 32×32 and 16×16 pixels along with layered Photoshop PSD file of the icons.
Signify Lite: Free Icon Font
Exclusive to MediaLoot, bring scalable and flexible graphics to the web with CSS @font-face and the new Signify Lite web font. With this font you have 38 beautiful, hand-crafted icons at your disposal for any use, you can use them in your designs in Photoshop etc. or on the web, and the beauty of icon fonts (besides the scalability and tiny file size) is that you can edit the colour, size, effects and more with CSS.
Apple OS X Lion Buttons in CSS
As you probably know, OS X Lion was released yesterday. While there are 250 some odd new features in Lion, what you probably notice first is the new interface design. Part of the new design is new icon buttons in apps like Mail, seen below. I'm going to recreate OS X Lion's buttons in CSS for use in your UI.
Retro Candy: Free Icon Set
This free icon set, brought to you by Jan Cavan of Dawghouse Design Studio, is inspired by a retro, hand-drawn theme. There are 18 icons in PNG format, sized at 200x200px. The icons include objects such as a chat bubble, a notepad, a martini glass, and more.
Free Google Plus Icon Set
I just came across an amazing Google Plus Icon Set that is available for free. The Google Plus Icons has 13 different social icons. Each icon of G+ from this set is available in different px size
Wooden Social: Free Icon Set
This free icon set, by WordPress Theme Shock, consists of 10 icons for social media sites, as well as common content-sharing icons like an RSS feed icon and an email icon.Each icon comes with its own editable source file (in .AI format) so that you can easily modify the icons as you see fit. The theme of this icon set freebie is centered on 3D and wooden textures.
Clean mono icons (vector PSD)
Friends, today’s graphic download is a set of 12 monochromatic icons in vector shape PSD format. These icons come in both normal and hover state, and each icon is isolated on transparent background in size 32×32 pixels for use in your web design needs. Since each icon is created using vector shapes, you can easily resize the icon. Download the mono icons set and let me know your thought.
18 vector web icons (PSD & PNG)
Friends, I’d love to share this freebie with you: web icons set in vector shape PSD and PNG formats. The set contains 18 excellent highly usable icons for your web works. Cool!
40+ high-quality (and free) icon sets
A great icon set can add a level of polish to your site design. It can be the cherry on the sundae, if you will. But a bad one, well, it can have the opposite effect. Luckily, Noupe has compiled a great resource full of 40 high-quality icon sets. Did I mention they come in PSD format and are also free?
