Today I had a lot of fun re-engineering a laptop case we bought about a year and a half ago. Some shipping monkeys dragged the box when the wheels got stuck, and instead of stopping just continued to pull the case, so the wheels ground down on one side. Now when you try to take it anywhere it clunk-clunk-clunk's really bad and is difficult to pull.
Unfortunately, the company we got the case from riveted the wheels in, so I had to drill them out and remove the wheels (they were rollerblade wheels). I replaced them with die-cast steel wheels I bought at Home Depot. I needed to get a few more parts, washers, etc to get everything to fit back in right, but when it was done, it rolled real nice. And these wheels aren't going to grind down. If anything, they're going to grind up someone else's floor. But if they're not going to take care of our case, why shouldn't we make it as strong as possible?