If you buy the Japanese Best Price release of Gyakuten Saiban 3-- cue the chorus of "don't buy it or Capcom won't localize the next one"-- you may be entitled to a set of reversible box covers for the whole series of DS releases. It looks like they're designed so you can store 2 games to a case.
However, the Gyakuten Saiban series already uses a consistent boxart design in Japan, meaning that all four of the DS games already match. And on top of that, the design for these bonuses is significantly less interesting than the original boxart. Of course, we're still getting this thing.
We wish it was nicer-looking, but it's lovely of Capcom to hand out bonus stuff in general. We hope these get included with import orders (that's right, we're ordering the import!)