Seeing image thumbnails when hover over the waterfall

I think Firebug and other tools do this already - basically, previewing images when you hover over the item in the list on the left of the waterfall or over the bars in the waterfall itself.

It helps a lot with visualization of what that bar represents and should be relatively easy to do since you already have an image map setup.

Actual resources can probably be taken from the source site and not stored on WPT, unless you want perfection ;)[hr]
I should mention that having it work on hover over bars in connection diagram is also very useful, not just waterfall.

Oh yes, I want this. Go Pat (and bunch of smart Google engineers) !!