Is there a method to pour espresso shots without damaging the crema?
If you're drinking the espresso shot on its own, you could drink it straight from the shot glass - or, better yet, buy an espresso cup, which should be about the same height as your shot glass. (A double-walled espresso cup will help keep it warm.)

If you're pulling espresso shots to be used in other espresso-based drinks (i.e., if you're adding some sort of milk or water to it), you could try an espresso brew pitcher, which basically looks like the sort of small pitchers you'd use to serve cream; they're normally about 3 oz, small enough that it would probably fit under your espresso machine. You could brew the espresso into the pitcher, then pour into your mug; the spout/lip of the pitcher should help preserve the crema once you figure out what the optimum pouring speed is. It should work similarly to pouring steamed milk: pour too fast, and the foam and milk come tumbling out all at once and you ruin the foam, too slow and the foam gets stuck in the pitcher. But if you pour just right, you should be able to pour most of the liquid first, and wind up with just enough liquid left to slide out the foam so it lands on top of your drink.