Oh, sure, I'll probably even start a blog out of this :P

Watch out, you're blowing your cover as lazy :)

Well this is just too interesting, and I should stop putting off this blog thing.

So? What have you learned?

It is possible, not specially hard, I implemented a Turing machine and a one-dimensional cellular automaton. You can program just about anything in a spreadsheet. I will later study the inner properties of the spreadsheet as a data structure and a programming paradigm.