jQuery Drag & Drop into a Text Area

Using jQuery, and looking to let user drag a placeholder into a text area.

Each placeholder is a <span> which has a class='placeholder'. The text area id is simply 'main_text'.

So, user should be able to drag each placeholder span on top of text area, drop it, and then text gets inserted.

Most desirable effect would be to insert text where they drop the placeholder, but I have pretty much given up on that one. At this point, just to get it working so it inserts the text anywhere at all would be a good start.

Has anyone successfully done this? Thanks -