Either, get a plastic microwave bowl, or get an microwave omlette maker.
Beat how ever many eggs and egg whites you need, place them in the microwavable dish. Add salt and pepper to taste. Microwave for 1 minute, move the egg around with a fork, microwave for another minute, start forking the egg so it fluffs, then microwave for another minute. Depends how you like them, you'll get it spot on eventually. I'd recommend a omlette maker for the microwave though, the kind where you add filling towards the end of the cooking process, then you just close the container and out comes an awesome omlette (great with tuna)