Well, my method leaves something to be desired but works well for me.  Since I relate mentally to my photos more by theme than date, I file in folders such as Local, Family, Vacations(named for the particular trip or holiday events), etc.   I also have temp folders for prelim keeping those which may be deleted later.  These themes are also dated .

In each folder are subfolders such as unedited, edited, etc.  All computer work on an image is in a subfolder within the primary folder.

I have similar folders on 2 external hard drives and regularly save to these drives.  When space is needed on the primary drive, a folder is deleted from the pc and all is on the externals.

The problem is recently coming up with a messy solution of too many temp folders.  It was too easy to upload to the temp folders and then these grew and became unmanagable.  So, back to a few temp folders and the rest in the theme/date filing format.  Works for me. 

Within a Renderosity folder are challenge, gallery(by year), forum post and more. These are routinely deleted except for gallery and challenge photos. These are edited duplicates of photos from the other folders mentioned above.             Tom.

Ahh. the .txt file is a fine idea!