Windows: If you like colour coding your folders by project, urgency or other markers, it's a huge hassle to do it through the default Windows interface. Folderico adds an icon-swapping menu to your right-click context menu for no fuss switching.
It isn't that you can't swap out the folder icons in Windows, it's just an enormous pain if you do it on a regular basis. Digging down into sub-menus on a per-folder basis isn't a hassle if you're tweaking your folders once in a blue moon but if you routinely swap folder icons or colours as part of your workflow going into the properties menu for each folder is far too tedious.
Folderico adds an entry to your right-click context menu-seen above — so you can switch folder icons and colours on the fly. Folderico includes the basic Windows 7 folder icon set and alternative icon set — you can add additional sets through the Folderico application.
One caveat regarding Folderico, it only adds the right-click menu in Windows 7 32-bit. You can install it and use the software interface to tweak folders on Windows 64-bit but that isn't much faster than digging into the default menus by hand.
Folderico is freeware, Windows only. Have a favourite tool for tweaking icons and folders? Use a colour-coded method for your workflow? Let's hear about it in the comments.