Evernote provides a free tool (limited monthly uploads) to categorize and catalog each student's work. In addition, apps are available for the iPhone/iPad in the app store. I have since created a premium membership and created a folder in Evernote for each of my students. My goal in the future is to allow students the opportunity to catalog their learning experience with Evernote but for the time being I will be using my iPad and iPhone to collect artifacts for the upcoming conferences.
To find out much more on how to use Evernote as an ePortfolio tool check out Rob Van Nood's blog about how he has used it in his classroom for multiple years.