pinguyos

Try sabnzbd Pinguy, you will thank me later. It decompresses the rars, makes a clean-up, you can format the name of the final file, setup the folders where they are stored with categories, read the nzb's from a rss feed, control it remotely, runs in a browser, and probably a ton of other stuff I'm forgetting right now.

And they give you the source to play with...