Moving plotted traces by hand

Does anybody know how to move a trace by hand? I swear by my life that I saw, with my own two eyes, someone simply click on a trace and drag it into a new position on the graph (my supervisor did it right in front of me, and we both can't figure out how it was done!). I want to arrange several plots on top of each other with some vertical offset that varies, and it is a time consuming process using the console to add constant offsets to each plot until it looks the way I want it. I am sure there is a way to slide plots vertically by hand after plotting them?
Try clicking on the trace and holding the mouse down for about a second. Then you'll be able to drag the trace around. Shift restricts the movement to just a single dimension.
741 correctly described how to do this. Note that we've had a few reports from users who say that suddenly the ability to do this stopped working. In most (or maybe all) cases this was fixed by them either rebooting their computer or updating their mouse driver. So it's possible that you're doing the right thing but are one of the few users who have something that causes this not to work in its usual way.
Thank you very much! I indeed have to wait upwards of one second, and then I can tell that I have waited long enough by the disappearance of the legend.