Nothing shows off the power of Mac OS X better than drag-and-drop, as support for dropped files is built into nearly every program. It should come as no surprise, then, that there are a number of commands that can be used to aid in the drag-and-drop process.
Command-drag
After dragging a file on the desktop while holding the Command key, the dropped icon gets instantly aligned to the invisible grid used to keep icons tidy. This is handy if you want to drag a bunch of files and make them fairly organized when they are put in their place.
This behavior changes slightly when dealing with multiple disks or mounted disk images. When dragging files in this case, the default behavior is to copy files, and holding Command forces them to be moved instead.
Command-Option-drag
When dropping a file and holding Command and Option, the resulting file will actually be an alias to the original. So, if you start dragging the original, hold the keys, then drop, an alias will be created at the destination point. When performing this command, an arrow appears under the mouse cursor to let you know what’s about to happen.
Option-drag
Similar to dropping an alias, Option-drag copies the original file to the destination. For this command, a green (+) symbol is placed under your arrow.
Command-Tab while dragging
I’ve saved the most impressive combination for last. It’s often useful to drop a file or two into a window of a running program, but sometimes this window may be obscured by other programs. If you start dragging a file, you can then use Command-Tab to cycle through running programs and bring the destination app forward. This is especially helpful when combined with Exposé, where entire programs can be whisked out of the way, a file grabbed, then dropped on the window of your choice.
Great Tips
Thanks!
Don't forget that command-dragging from one disc to another disc "moves" the file. The file is deleted from the original disc and a new file is created on the new disc.
It'd be nice if there was a way to pop up a context menu of the various drag-drop options, a la Windows. Yeah, flame me, but have you ever tried some of these gymnastics on a friggin' track pad?