How do I keep Last.fm from scrobbling podcasts? I would like to use last.fm to just keep track of what music I listen to, but I listen to a lot of podcasts as well, using both iTunes and my iPhone.  Is there any way to prevent the Last.fm application from scrobbling my podcasts?  Or alternatively, is there any way to prevent Last.fm from scrobbling any music file longer than 1 hour or something?
Open the Last.fm application.
Menu item "Last.fm -> Preferences"
In the Scrobbling page, edit the "Scrobble Directories" and make sure that your podcast directory is not selected. If you have your iTunes library in the standard location: Expand the directory tree to find /Users/you/Music/iTunes/iTunes Media and make sure that the directory Podcasts is not selected.
Review the other directories that are selected, for example you might want to make sure that the Audiobooks directory is unselected.
OK!