If you're the type to have three or four different projects going at once, then chances are you run out of desk space pretty quickly. Instructables user Neurogami never has enough room on his own desk, so he created a simple interchangeable system using plastic serving trays.
The idea is to create an easy-to-switch-out work table for smaller projects. Each project type gets its own serving tray and when Neurogami needs to change gears and move onto something else, it's as easy as picking up the tray and grabbing another one. This means cleanup isn't a necessity and it ensures a small desk can handle multiple projects at once. Of course, you will need a good amount of extra storage for this to be useful, but if you have more shelves than desks, it's a handy trick.
Managing limited desktop space and multiple projects [Instructables]