The one poster showed a pic of his bench with wheels.  Use the same concept for a Tool Tower, wheels on Bottom, racks on 3 sides,, and 4th side open to hold tool boxes, etc. Hang all tools on 3 sides with peg boards or whatever,regular tool boxs in shelves on 4th side, expecially in larger shops, when working on a piece of equipment all or 99% of the tools roll right to the Machine.

Saves that 400 trips across the shop to get that needed "1 more tool". Plus it's easy to roll around when cleaning out the shop.