At one response every 5 days, it might be worth reading in a month or so.
I forgot to mention the Lingering Song exploit - I suppose it's technically possible to get DR in the hundreds for a very short period of time - but I'm interested in legitimate DR-stacking.
I may do some experimentation when I have a chance (which will be months from now - anybody else feel like doing it?) to see what exactly stacks. Complicating matters is that some DR effects are "better" than others in terms of protecting against various levels of weapon enchantment.