I had the most brilliant flash of inspiration. Almost certainly I'm not the first to come up with something similar, but I think it's cool.
So here's my idea.
You will need: drawing pins (this kind are probably the best for the purpose, and ideally you want as many colours as possible), thread (again, many colours is helpful but not essential, and fairly coarse thread is best), and a large rectangle of something you can stick pins into nice and firmly without them coming loose.
We're going to make a space-time continuum.
It's helpful to draw grid-lines on your pin-board, or stick a sheet of squared paper over it. Now draw a timeline along one side of the paper, and a list of settings on the other. As far as possible, you're going to want to try to make the distance between places roughly correspond to the actual distance between them, but since you're laying out a two-dimensional world on a one-dimensional line, it's not going to work out perfectly. You could in theory do this with a 3d plot, especially if it was done on a computer instead of a kitchen table, but it would probably just turn into a tangled mess, when the point is to be able to see things at a glance. But the spacing of the locations is not hugely important anyway.
Now, for every event or scene, stick a pin in the appropriate point in spacetime. Some labelling system will be necessary. Different colours are useful to see at a glance which one is which, but not important, and you're unlikely to have enough colours to make them all different anyway.
Now, the characters. For every character except bit-parts who are only in one scene, tie a length of thread to the pin where they first appeared in the story. Then take the string to the next scene they were in, and wrap it around the pin. And so on. If they die (or in some other way get written out), tie off the thread at their death scene.
And there you have it. I call it a plot-web. You shouldn't have any thread visiting two different pins that are level on the time axis, or two pins a long way apart in space within a very short time, unless they have access to teleportation - that's why it's good to have nearby places close on the location axis, so you can tell by the gradient.
If you don't want to bother with pins and thread, you could just draw dots and lines on a sheet of paper, but the pins are more fun, and you can move them around if you change your mind.
Whaddayathink?