I found some cubes at London Drugs in Brentwood Mall, Burnaby, BC the other day made by Rubbermaid, and they were heavy! My mom had cubes back in the mid 90s that were made of 100% plastic and were pretty light and all, and that's what I was expecting however when I tried to pick up this 12 pack they were just really really heavy, like plastic coated steel. Is this normal? Or should I shop for other brands? I have to build a 2 storey structure on my desk which I bought last year which is built of 3/4" particleboard wrapped in veneer... it's really weak stuff and I had to replace my 19" CRT with an LCD monitor earlier this year because the weight of the monitor was causing the desk to bend downwards. I'm expecting that if I buy enough Rubbermaid cubes or more, they will become heavier than the 19" CRT monitor, albeit spread out in a 28"x56" area. The only advantage i can see to using the Rubbermaid ones is that I can bend them -- good for stairwells, hay racks, etc... but perhaps these Rubbermaid ones will be more able to handle the weight anyway... Any thoughts?