Bunny and I got into a heated discussion over the proper way to clean a cast iron skillet and in the end, I had to do some searching. So, for the record, the proper way to clean your cast iron cookware [1], and while we're at it, reseason (or recondition) your cast iron cookware [2] (even if you think it's given up the ghost [3]).
[1] http://blackirondude.blogspot.com/2008/12/cleaning-your-cast-iron-cookware.html
[2] http://blackirondude.blogspot.com/2009/01/easy-cast-iron-skillet-reconditioning.html
[3] http://curiouskai.blogspot.com/2009/12/reconditioning-cast-iron-frying-pan.html