I just received a 42u rack from my work. We're no longer using it and were just going to throw it away. The rack is very similar to this :

As of right now my lab is in my spare bedroom, which has carpet. I was just wondering if anyone has built anything to stabilize their racks or if there's anything I can do to not let it fall over. Now, please don't state the obvious with drilling bolts into the ground - I already know about this. At the moment I rent a house, and I don't think they'd appreciate me drilling 1/4" holes in ground.