Sushi and soy sauce go together like chocolate and peanut butter, or meat pies and tomato sauce (i.e. -- one is made infinitely better by the other.) Unfortunately, soy sauce can also be horribly messy; especially if you're snacking at work sans plate. Here's a simple tip that should keep the drippings to a minimum.
As the above video demonstrates, all you need to do is stripe your sushi with multiple thin lines of soy sauce. Easy, eh? Another benefit of the 'zebra' method is that your sushi will have an even distribution of sauce, which translates to no more bland mouthfuls. Banzai!