Protect your stuff? How about protect your parents? Get an electrician in there pronto!

You have to be kidding when you say you have seven appliances connected to one outlet? Are you trying to start a fire?

I'll bet your folks also have aluminum wiring throughout the home. Please, do the safe thing and have a professional look at this home. I'm sure it's not to code either.

if you wade through the spam . . .

You may be able to add grounded outlets. Check with an electrician, but if the outlets are wired with BX cable (the metal houseing around the wires), you may be able to use that as a grounding wire. Then you can put a three-prong outlet in, and use it normally.

I would suggest adding outlets,though, since extension cords really shouldn't be a major solution.

Check with an electrician and see if there is a ground wire tied to the metallic box behind the outlet. I have worked on some houses built back in the 60's, and realized that the electricians had tied the ground wires to the back side of the electrical boxes. My coworkers and I have pullet the ground wires through, and used grounded outlets.