A PAC-file workaround for proxy use in OSX

As a big user of proxies in China, I really grew fond of the FoxyProxy extension for FireFox once my good friend Alex exposed me to it.
It allows you to set rules for when to use which proxies.

This can be a big benefit as many sites in China work fine and you don't want or need to use a proxy to see them.

I have historically used FoxyProxy with Secure-Tunnel and had great results.
Their software is usable through their windows client software or through any SSH client that supports tunneling.
It is not a free service, but worth it if your business depends on reliable International Internet connectivity.
They also over Site-to-Site solutions meaning you could configure, as an example, the router in your Rep Office to send all traffic over secure and reliable links.

But, when recently switching to OSX, I decided to make (albeit futile) attempt to stay with mostly Apple provided software and thus have grown accustomed to Safari, Apple's provided browser .

The only real limitation for me in relation to FireFox (besides a few useful but not necessary extensions) is that it doesn't have flexible proxy support as provided by FoxyProxy nor does it have a plug-in for it.
There are some interesting plug-ins available for Safari like Saft and Pith Helmet but none gave the proxy functionality I was looking for.

I believe this is due in part to Apple's decision to leverage the OS-level proxy support for Safari rather than have it be included in the browser code itself.

In my travels to get rule-based proxy settings workable in OSX, I came across the Configure Proxies: Using a PAC File option.

WikiPedia has an entry for these types of configurations.

Has anyone ever attempted to use a PAC file to direct certain URLs through a proxy and others not?

I am very interested in using a PAC file as a method for providing Proxy rules to Safari and this might be a viable method.