Back in the 1980s people were trying to do everything with spreadsheets. (A more recent book on using spreadsheets to do physics calculations is: Doing Physics with Spreadsheets, Aubrecht, et al, Prentice Hall, 2000.)
The May 2005 issue of AI Expert Newsletter (www.ainewsletter.com) was devoted to spreadsheets, but devoted mostly to neural networks and automata. Many more AI methods have been implemented as spreadsheets:
case-based reasoners (Freedman, et al, page 296, Proceedings of the first inter. conf. on AI app. on wall street, IEEE, 1991)
clustering (Aravind, et al, Inter. J. of Comp. App., vol. 11, No. 7, Dec. 2010)
Markov chains (Ching and Ng, Markov chains, Springer, 2006)
I've deployed a version of chained case-based reasoning (see chapter 3 of my book Twelve Papers, www.robert-w-jones.com , book) in Excel.