CanLinkIt is now obsolete, as of Adobe Photoshop CC version 14.2. As of this time we will cease mantaining CanLinkIt and recommend you upgrade to Adobe CC's Linked Smart Objects. Native Adobe integration is going to be much better than any 3rd party plugin can be. Enjoy the new feature!
Download The Beta Now -- it's free!
With the CanLinkIt plugin to Photoshop, you can link any PSD or image file photoshop files to another. With one click, you can update to the latest version or even update all links. For example, if you used a button in three places and then update the style of the button, with only one click of "Update All" you can update all three!