Gerard 't Hooft, who got the Nobel Prize for work that made the standard model possible, has been writing a series of papers in which he tries to get quantum field theory from a classical cellular automaton. He described a bosonic theory in May and now he has a fermionic theory. It's quite deep, because he's trying to get reality holographically, from the "worldsheet" of a superstring; that is, these cellular automata are 1-dimensional, and describe degrees of freedom along a string, and macroscopic space is built up from these. String theory already works that way (that is, instead of a string moving through space-time, you can view it as fields evolving on the string, one field for each space-time coordinate), but normally one supposes that the fundamental theory is still quantum. It's hard to believe that these ideas could work exactly as outlined, but it's the beginning of yet another line of inquiry.