I have installed a number of blogs, each in a separate subdomain. I would like to set up a single themes directory (in my root or elsewhere) and have each of the blogs look there for style info. The intent is to be able to tweak the custom themes that I share between blogs, without having to make the same tweak for each installation. How do I go about redirecting where the blogs look for the themes directory?
(Yes, I have looked into wpmu. Unfortunately, my hosting plan doesn't support the requirements.)