Originally Posted by Gumby
I'm pretty sure that no one in the subsequent generations of my own family ever will care about my memories of life.
I don't know, I have a great uncle who had no children, but he left a collection of his letters written to his folks, his sister (my grandma), and his future wife while he served in WW II in Australia and New Guinea. They are fascinating and I'm glad he saved them.
I have an ancestor who was born in Western Massachusetts and took the Erie canal with her family to migrate to Ohio. Later in life she wrote about that journey and the first year at their homestead where they almost starved to death because of a killing frost that wiped out their crops.
Personally, I don't think the format is that important. They key is to write things down (or record audio). Preserve the memories.