If you're like me and browse a lot of image based sites such as Dribbble, Reddit, Flickr and 500px you already know how time consuming and annoying it can be having to click on images to see the larger version. Especially on somewhere like Reddit where you can only see a very small thumbnail before even clicking on the Imgur link.
Hover Zoom is a must have extension for those who go through tons of media every day and don't want to keep having to click on images or open them into new tabs.
When installed, you simply start hovering over an image and it'll very quickly show the enlarged image if there is one available. Depending on your internet speed, the loading of images can vary but usually I've found it to be very fast and not very resource intensive.
You can also disable for certain sites if you find it annoying which is great.