Enter the Caffè Macchiato. It's a demitasse of potent espresso topped with a healthy cloud of foam. If you are especially caffeine-deficient, you can whip up a large version in a regular size coffee cup and call it a Doppio [Double] Macchiato.
The easiest way to foam such a small amount of hot soy milk is with a handheld frother.
Handheld frothers are perfect for city kitchens or for anyone who lacks counter space. They take up very little room and you can store them in your utensil or junk drawer.