A quick Google search rendered two respectable solutions:

• http://snag.gy: Allows you to paste an image and get a link. There are also some basic image-editing tools.
• http://pasteboard.co: It’s supposed to be the same as Snaggy, but also allows you to drag images. However, it failed (by way of stating that I was only allowed to drag-and-drop an image) with the four- or five-images that I attempted. I’m assuming that it detects whether you’re dragging an image based on the file-extension. If the file-extension isn’t present or there’s an inconvenient period in the filename, it will likely reject it.