It's not 100%, but we have made some progress....
Wes found a memory card recovery program and was able to recover 500 pictures from the card in our Nikon camera! It recovered the last pictures that were written on the card. The most pictures we had on the card at one time was right at 500. (the 2G memory card will hold up to 585) I burned them to the Hard Drive and deleted them. Then we started over the next day. So we have pictures from Munich, a few from the Eagles' Nest, and then some from Rothenburg, Nurnberg and Salzburg. We don't have any from St. Goar because those were the first ones on the card and they were written over.
I feel a little better now. There was a really good one of us on top of the mountain at Eagle's Nest, but unfortunately, it's not there. (We ran into a family from Texas and we took each other's family photo.) Oh well. Like Wes said, we learned a valuable lesson this trip. We should have brought more than one memory card for the big camera and we also should have kept the hard drive in our carry-on bag.