Jason wrote up a great follow-up article, Investment Spreadhsheet 2.0, to his original post, The FU Money Spreadsheet, over at Hackszine.  Some added features to the FU Money Calculator 2.0 are fields for accounting for your 401k contributions and a home loan. 
Jason describes 3 scenarios in which normal people like you and I can become "wealthy be being excessive in our frugality."

Previously:
The FU Money Spreadsheet (post on Blogcadre)