Yep. Dusting. I did it three weeks ago. Still coughing the dust up...
I use the portable vacuum first, then the duster :-). We wouldn't have so much dust, except that things are always being piled up on the head-high surfaces, away from the younger children, and sometimes they don't get cleared up for a long time. I found several treasures when I got to the far reaches of the top of the TV cabinet, which is where I'll put the Advent wreath tomorrow.
I shudder to think what's out of sight on the 7' bookcases, but I'll find out when Der Prinz decides it's time to paint the schoolroom!