MY 1g memory stick only has 438mb of space and yet there is nothing on it. How can I format it?

If your memory stick is formatted into a specific (I think fat32 but don't quote me on that) format, usually it will reserve half as a mirror copy in case of failure you can retrieve your data. To format it, go into my computer, right click on your memory card and hit format, uncheck Quick format and select the file format of your choice.