Hi,

 I think that a very nice enhancement could be done to copy/move operations when using the file explorer. When a copy/move operation is in progress, new copy/move operations should be QUEUED instead of executed in some circunstances, such as:

- Copy/Move source is the same as the source in any copy/move operation currently being executed.
- Copy/Move destination is the same as the source in any copy/move operation currently being executed.

 Think in those situations:

- You're copying a big file from a DVDROM (call it "copy source 1"). You continue browsing the DVD, and you want to copy more big files. You select another file and drag it to the destination. Then, as the "copy 1" is still in progress, the CDROM starts to "spin" moving from "copy source 1" to "copy source 2". Both copy operations slow down due to CD beam moving between different disk positions.

- You're copying big files to a local HDD drive and you plan to leave the computer "copying" while you do some extra things away from the computer. All files are not in the same source folder, so you can't just "select" all simultaneously. You drag & drop the first one (which starts copying) and you move to another folder to drag & drop another file. Then, the disk header of the local drive you're copying the files to starts moving between the 2 destination sectors in the drive. If destination drive uses FAT/FAT32 fs, filesystem can get fragmented. And the time needed to copy both files is larger that the sum of the times needed to copy both files separately (due to disk header movement).

 The ideal when using the GUI of a file explorer for all those situations should be:

- First file operation starts inmediately (source1 -> dest1) .

- When you drag&drop the second, third, ... files, if source == source1 or dest == dest1, the copy/move operation would be queued and delayed until the first operation ends. If source and destination are different then the copy/move operation can be done simultaneously to the current active operation.

- Queued operations would appear in the screen just like any active operation, in a "copy" dialog similar to current copy dialogs, but status bar would show a text like " Queued ", and would include a button to unqueue and execute them if the user wants to. Like the current "File operation in progress" dialog for nautilus, where extra copies are added below the existing ones, in this case "Queued" copies would be added, plus the current "Cancel" button and an extra "Dequeue/Start copy" button.

- All this behaviour could be configured as an option in "Preferences" (Something like [X] "Queue I/O operations using the same source or destination than active operations").

 I do really think that the above behaviour would be very interesting and would solve lots of slowdowns and problems when copy from/to CD, DVD, flash drives, USB disks or even local harddrives.

 Thanks a lot :)