WinDroplr is a free Droplr client for Windows. WinDroplr lets you share files, shorten URLs, take screenshots and share on web, all with one click. When you install WinDroplr on your PC, it adds an icon on your desktop. If you want to share a file with your friends, you can just drag and drop to the icon. WinDroplr will immediately upload it, and will give you a URL for the uploaded file that you can share with your friends.
If you drop multiple files to WinDroplr, it will zip the files, and upload them together, and will give you the URL to share. All these happens automatically, and you just have to drop the files on to WinDroplr icon on the desktop.
To use WinDroplr, you can login with your Twitter account. It uses OAuth authentication of Twitter, which means you do not need to create a separate account (it gets only read-only access to your Twitter account).
WinDroplr works a lot like CloudApp, and Cloudapp client for Windows. As with FluffyApp, WinDroplr can also take screenshots, and upload them to web and will give you a shortened URL for that.
WinDroplr is a really good application if you share a lot of files with your friends, or post screenshots on Twitter. WinDroplr is completely free. Here is a small video that shows how to use this free Droplr client for Windows: