I recently imported all my photos from my external drives into Adobe Lightroom and sorted them into folders. What this did for me was give me the ability to search all of my photographs in Lightroom as well as edit and export quickly and efficiently. If I need to look up a photo I can use the Lightroom metadata search feature to quickly find the photos based on any number of search parameters (date, location, camera used, lens used, camera settings, etc).
Its really simple to set up and maintain and using the synchronize feature keeps both your Lightroom catalog and the actual files on your external drive up today and the same. In addition to being more organized it's also a streamlined way to upload photos to the internet via the "Publish Services."
Check out the video below for an overview of how I have my catalog set up now.