Update-1: (Dec 1st,2010) This project has been published on CodePlex: http://spdragdrop.codeplex.com/
Update-2: (Dec 3rd,2010) ’Moving Folders’ support implemented, and published.
Update-3: (Dec 13th,2010) ’Delete Documents’ support coming soon…
Here is a cool jQuery functionality which i have been working on for a while to adapt to SharePoint document libraries. It’s multi-select drag and drop for SharePoint documents. As of now, I managed to hook up this with move operation but in theory any method can be called upon drop action of selected documents.
Here is a teaser screen to show how it looks like..
* Draw a box on documents you want to select. You’ll see that icons of selected documents will be highlighted showing that they are selected. You can also use Ctrl key to select/deselect other documents just like in most operating systems.

* Drag selected documents and drop them onto a folder icon. All selected documents will be moved to that folder.

* As a result of drag&drap, all selected document are moved.

This functionality is using jQuery UI, FronPage RPC (FRPC), and AJAX.
jQuery UI–> multi-select, drag&drop
FRPC –> move document
AJAX –> calling RPC methods.
Soon, i’ll publish this solution on codeplex as well. I’ll be glad if you share any feedback such as other useful scenarios, areas of improvement… etc.
Stay tuned!
zieglers
UPDATE – November 30, 2010
Move Multiple Documents
Move to Folder
In case you want to move multiple documents, you can select them by drawing a rectangle box as seen below.
Selected documents will be highlighted as you draw the box.

When you drag selected documents over a folder, destination folder will be highlighted with dashed lines informing user that it’s an acceptable dropoff location.


Move to Document Library
Alternatively, you can move selected documents to any document library listed in quick launch menu. Once you drag selected documents over a library, similar to folders, library links will be highlighted as well as shown below.

Move to Parent Folder / Sub Folders
You can also move documents to any sub folder in a document library. In order to do so, simply drag selected documents to any sub folder breadcrumb link as seen below.

Technology Used
jQuery, jQuery UI, FrontPage RPC