Could've sword I replied to your post, but I guess not.
The plugin actually started out as being largely independent from the
WordPress system. The plugin was originally based on another script
that used Magpie to retrieve the RSS feeds. I discovered that
WordPress had Magpie built-in, so it simplified the install process.
The plugin now uses a WordPress hook for curl/fopen to grab images for
the cache. Anyway, it's mostly a matter of pulling out the WordPress
specific bits and hooking things into Magpie. The most recent version
of the plugin largely separates the WordPress settings page code from
the rest of it, so things should be a bit easier to understand.