Old cabinets are great for storage in places like garages and sheds. One of the best
ideas I have seen though, was a doll house. Use a small cabinet unit, and paint the outside
like a house, and finish the inside with scraps of wall paper and carpeting. You can often find
old wall paper books and carpet samples free.
Take the old cabinets and sand the exterior with sandpaper. Primer and paint with a quality high gloss paint and install them in your garage or workshop for extra storage.
The old cabinets will make great storage space in your laundry room, garage and basement. Another thing that they're great for is for a pantry. Even if you don't have a pantry, you can use them for storage of canned goods or paper products, in your laundry room.
In my opinion, I would select those of a suitable configuration and place them in my workshop. You can always use the extra storage, and used cabinets should fit the bill.