Is it stumbling at all? In other words, when you crank, does it sort of start to catch, then die, start to catch, etc... or does it just crank and crank and never seem to grab?

If it's stumbling, then at least you have SOME spark. But if it's not even stumbling, then you're either getting (a) no spark whatsoever, (b) no fuel, or (c) no air (doubtful).

The first step would be to determine if you're sparking at all. Pull a plug out, ground it, and see if there's spark (or use a tester, or whatever means you want to .. just see if it's sparking or not). Sounds like you may not have spark on any cylinders at all, in which case you probably messed something when you were playing with the distributor (probably an easy fix).