For most things, the simple answer would be no. Powdered ginger does not contain nearly the kick that fresh does. If you have trouble keeping fresh ginger in the house (it always goes bad on me), there is crushed ginger in a jar like a pp suggested, or try to get ahold of ginger juice by the Ginger People. Alternately, depending on the recipe, crystallized/candied ginger may work.
Whole ginger can be kept in a jar of wine in the fridge. Take the hand of ginger, break it into smaller chunks (I peel it, just scrape with a spoon), drop it into the wine (to cover), refrigerate. It will keep months like that. It does take on a bit of a wine flavor, but in things like stir frys or marinades that's not a problem.