You know you ve been there!
You have a friend over and he brought his protable hardrive etc and theres a ton of stuff he wants but is spread out all over your ssytem on diffrent harddrives, both local and on your LAN etc and you have to sit and copy folder or file by folder or file from all the different places manually.
Instead, how about being able to drag n drop something you want to copy to a little window hovering next to explorer and then, when you ve dragged n dropped everything you wish to copy over to a specific location you just press a button and the copying process starts and you and your friend can go have a cup of coffee instead of hovering in front of the computer waiting for stuff to finish copying so you can begin copying something else from another folder/drive.