Mac OS X Hints: Spring Load Your Dock
This is a great hint that can help make your workflow go a bit more smoothly. I especially like it when I’m uploading items via ftp. After you do the Terminal command, if you hover over a dock icon while dragging a file:
. . . the item will open and be shown. So if you hover over an app, it comes to the front and you can drop things onto its window. If you hover over a folder, you can drop into it. If you hover over a file, it will open the file and bring that window to the front. You could, for instance, drag an HTML page onto a web browser, and then to a previous tab to load that page in that particular tab. Or, you could drag an image file to drop into a rich text document at a particular location all in one fell swoop. [From macosxhints.com]