In case anyone needs it for the future, here's where the setting can be found: Nautilus File Browser -> Edit -> Preferences -> Media Tab.
When I first connected my iPod to Mint, I got the dialog box asking me what application I wanted to use to open it. I chose Rhythmbox at the time, and against the judgement of the little voice yelling in my head "you're not going to know how to change this later!", I went ahead and clicked the "always use this application" box. Sure enough, that voice was right. At this point I'd rather go with Exaile. How do I go about changing that setting so that Exaile opens instead of Rhythmbox? I looked through the Preferred Applications settings, as well as changed the "Open With" choice on the iPod's folder in the /media folder, but no luck, Rhythmbox still opens each time. Thanks for any suggestions.