KEITH NEALY Cast Away is incredibly useful. I can set it up to get rid of podcasts automatically and so just let iTunes and Cast Away keep me up-to-date. I just sync my iPod to have all the latest stuff without having to worry about it filling up.
The developer is very responsive and worked with me to add the ability to handle SmartPlaylists and resolve some timing issues.
Highly recommended.
(Version 1.9.2r2)