I had (quite wrongly) assumed I could use iSync to synchronize the main folders I use on my laptop and desktop–my e-mail folder, and my main project folders–but it turns out iSync only handles your calendar/contact info.
Is there another utility/app I can use to accomplish the above? (i.e., make sure that specific folders on my laptop and desktop have the same contents)
If you don’t mind using the Terminal, then “rsync” does just what you want. You could probably use Automator to write the shell commands that rsyncs the directories you are interested in, and run that Automator workflow from the desktop.
Open the Terminal.app and type “man rsync” to get an overview of what the command is, and how to use it.