I love office supplies of all shapes and sizes, and older steel case cabinets and desks are some of my favorites. I adore the idea of resuscitating them and painting them jubilant colors. Bringing an old file cabinet into the kitchen? I'm intrigued...
I really love the look of this rolling kitchen cart, and think that the size might be just perfect for a versatile surface that doesn't take up too much room. My kitchen is not very large, but I would definitely have the space (and the need) for a cart of this scale.
Take a look at the step-by-step---it doesn't seem like too much to handle! And regardless of whether a filing cabinet works for your aesthetic, it ought to get your brain working to think of other non-traditional items that might be transformed in kind.