large wood dowel rods from Home Depot. My patient husband cut tons of disks from the rods, carefully sanded them down and glued them in place on the bed. Then we primed and painted the different sections to look like gigantic Lego pieces.
Great storage idea for your LEGO fanatic.... Take yellow bins from the dollar store and draw LEGO faces with a black Sharpie. Put a drop of white paint in the black of the eyes for a more authentic look.