Ladies, I have an idea. I've started a spreadsheet on google. Here's the link. You can update and add your measurements without signing in to anything.
http://spreadsheets.google.com/ccc?key=pXi7yo0_PbN2UTgZxZBQ_Kg
No, that's not a dumb question! I think it's a common question and the reason a lot of people haven't added their measurements already! I have the soft measuring tape seamstresses use but you could use hard measuring tape, it would just take a little longer. Use a ribbon/thread/shoelace to measure the insole (along the contour) then measure that with your hard tape