They now make an anti-nausea liquid (there are several generic brands) that really helps with the top end, and as was mentioned, Kaopectate or Immodium helps with the other.
When the nausea is worst, drinking any liquids makes it worse, so popsickles, slurpies, or even just a cup of crushed ice are best. Once you can get liquids to stay down, Gator Aid or a similar sports drink is helpful.
When you are that sick, your stomach doesn't really need to handle food, so don't force yourself to eat. I remember telling the doctor over the phone once, that I couldn't keep anything down, and he said, "So don't eat!"
I was interested in everyone's suggestions...there were some good ideas. Soda crackers are the first thing I recommend, because you can slowly nibble one at a time, and see how it goes down.
I don't think anyone mentioned Jello, though. Once the worst of the nausea is over, it's a good source of protein. Old fashioned Cambell's Chicken Noodle, which is pretty salty, and a grilled cheese sandwich (made in a non-stick skillet without butter) always tasted good to my kids once they could hold some food down. Velveeta or American cheese is best because it's bland and easy to digest. Now that we having cooking sprays available, I often make grilled cheese without butter or margarine anyway.
And sympathy, sympathy to you and Mrs. BigDog...it's so awful when your body revolts on you.