I've always been partial to dashboards and often write about it. I've done a number of prototypes just to experiment with visualizations.
Dashboards allow you to organize and see the information you want without adding too much clutter.
Here's my implementation. It works in IE, Firefox, Safari and Opera.
I particular like the visualizations found in the iGoogle and Newsvine dashboards. They provide nice feedback on the container that you're moving and where you'll drop it. So, I've copied that.
When you move a container, everything is **real** size -- not a sliver for where you'll drop the container. For me, the argument that you cause too drastic of a visual change to the layout doesn't hold water.
You're only moving one container at a time and it's not a common operation. You basically move a container, get it into the fold and view it.
You're also only dealing with a **few** containers. This is a dashboard.
My implementation uses YUI 2.3 which easily handles drag over with the drag and drop library.
In this case, a drag over, inserts a temporary marker above the container.
When you drag out, the marker is removed and the container list collapses ( each container is statically positioned ).