How many times do you copy something just because you want to paste it somewhere else, immediately? Only, you get yourself into quite a mess if there's something valuable already on the clipboard. Sure, there are tools out there that allow for multiple clipboard items. It's built right into Office and even Visual Studio. But who uses that feature really? They're... clunky. For me, I always end up running a quick Win+R+notepad+Ctrl-V. Ahh the endless uses of notepad... but anyway.... all this madness and all you want to do is get something from ------> here
Why must it take at least 4 coordinated strokes of the keys to do it? Control-C, put hand back on mouse especially if you're a southpaw ('C' is on the left side), Control V. And you overwrite your precious clipboard contents to boot. Hopefully that content wasn't sensitive, because you betcha you aren't going to take care to clear the clipboard contents. You know what I'm talking about... ever hit paste, then go, "oh yeah... I remember that." For fun sometimes I hit paste at public ter- ... nevermind.
Drag and dropping with the mouse sometimes steps in to save the day. Instead of copying and pasting that item, you could drag and drop it to get over there... no clipboard involved. It's refreshing when that works, isn't it? For example, you can select code in Visual Studio and drag the selection to another part of the source file... quite handy, especially when you are trying to save whatever may already be in the clipboard.
When you think about it, what makes it handy is how few operations it takes to accomplish, not the fact that it's a mouse based operation. You push in the mouse button, then you let go of it... jeeze, it can't get much better than that.
But the mouse isn't the only thing that you can press and depress, right? Not that the keyboard isn't already cluttered with useless keys, and some keys that are arguable. But my suggestion I think would be a great addition.
A CopyPaste button.
Select what you want, hold down the button, then release when you're done. No pesky clipboard required.
If you imagine doing this in combination with the mouse it doesn't seem that useful... you could just press the mouse button down as already described, as you move from 'here' to 'there'... if you've already got your hand on the mouse, that's easier. But if your hands are already on the keyboard, and you can easily get from source to destination with a quick Alt-Tab or arrow key navigation, this would be a huge time saver.
It isn't an original idea I'm sure... the concept of using the keyboard's intrinsic up/down nature is definitely not new. For example, the uber-useful Alt-Tab and Ctrl-Tab.
This goes along with my desire for a left and right mouse click button on the keyboard. For windows keyboards you already have the menu key, which is similar to a right click, but it activates based on the keyboard selection instead of the mouse location. The problem with clicking with the mouse is that it's actually a very unnatural thing to do IMO. You must hold the mouse in place while applying pressure to it... often times, you cause the mouse to move inadvertently while doing this, especially if you are attempting a quick double click, causing you to miss your target.
Aside: A funny story... at my very first job, I was a tech support agent for a nameless ISP. I once spent over two hours on a single call, much to the supervisor's discontent, because the poor guy kept missing where I told him to double click. How on Earth he was planning to get along on the internet is another story... accessibility wasn't exactly mainstream back then. In the end we got him up and running. Then, I stood up and quit. I worked for Dairy Queen for the next two years. No I'm not kidding :)
But a button on the keyboard would allow you to do this separately from the mouse, allowing you to be confident in the click's location. How often do you type something while moving the mouse? I can't even think of a scenario where one would do that. So, your other hand is doing nothing... yet for some reason we require you to click with the same hand that is already busy? Bah!
I attempted once to write something to reprogram my right control key into a left mouse click (again, I'm left handed...). Alas, global keyboard hooks are not my forte and I gave up...