You let Disk Inventory X scan your hard drive and it creates a visual representation of the used file space on your disk called a treemap. Each of the colored blocks represents a file on your hard drive. They're color-coded by file type, allowing you to visually distinguish documents from media files, applications from fonts. The size of each of the blocks is proportional to its file size, meaning that the bigger the file is the larger the block, which allows you to quickly identify large space hogs.
The large purple square in the image above represents the sparse bundle used by FileVault, but you can easily see the digital copies of Inception, Star Trek and Tron Legacy I have stored in iTunes outside the FileVault. Once you've identified an errant large file, click on the block to display information about the file including size, creation and modification date, owner, permissions, file path and format. You can then either reveal the file in Finder or trash it straight from Disk Inventory X.
While you can find large files manually with Finder, Disk Inventory X streamlines the process. Download the free Disk Inventory X today and reclaim some of that valuable hard drive.