One of my favorite features in OS X is the ability to drag pretty much anything, drop it on pretty much anything else, and have the item be contextually useful in some other application. So pervasive is this gesture that we even waxed romantically about it some time ago. An example of this would be dragging an image from Safari onto an iChat window, allowing you to share the image with one of your buddies.
Enter Droplr. This tiny application sits in your menu bar and allows you to drop all manner of files onto it and share them via a variety of venues such as Twitter or email. The tagline "drag, drop, share" is about as accurate as one can get when referring to Droplr's simplicity in file-sharing. If you're intrigued, head on over to the Droplr homepage and peep the screencast they have made available.
The Snow Leopard-only app and hosting service is available now for free (as in ad-supported) with 1GB storage. Don't be surprised to see a for-pay option with no ads and additional storage in the near future. Go check it out and let us know in the comments how it works out for you.