I bought some cheap utility shelving units from the Borg a few years
back. The frame is snap-together angle iron, with particle board
shelves. ... Pretty ugly, but good enough for utility storage in my
basement.

I have many shelfs like that in my basement. But I don't want to use
them in a woodshop because I have a feeling that everything on the
shelf will be covered with dust soon (despite my effort in dust
collection). Therefore, I am planning to use shelfs that are covered
in all sides and with a door (and a lock to prevent my kids from
fooling with the sharp tools). Thanks for the idea anyway.

Jay Chan