I keep a project list of ideas, actual projects, progress dates, and finished dates.
I also take pictures and put them on Picasa..if my computer crashes, at least they are still there. I have missed a few at the beginning, but have most of them. I have started a blog and have them on that also.
I also started putting pictures of quilts in frames and hang them on the wall in my sewing area...right now I am a little behind in that.