The best mnemonic device for remembering the last six ranks in the three domain taxonomy of life comes from the Comedy Central show TV Funhouse. Though some what vulgar, it is utterly unforgettable. Note that I refer to it as vulgar merely because of the explicit sexual reference, not because of the sexual orientation of said reference. Anyway:

If you find you have trouble remembering the first two, domain and kingdom, just think add Don King to the front of that.