Windows only: Xinorbis is a portable and quite powerful disk analyzer. Graphs, tables, trees, and report generation ensure you know what is going on with your data. After scanning your disks—the results can be viewed individually for each drive or merged together to provide a system overview of all your storage—you can drill down into your data. Data can be sorted and graphed by file type, biggest folders, date of creation, 101 biggest and smallest files, and data distribution by user. Results can be saved with the Report function and compared to future scans. Additionally there is a basic file navigator that places a handy bar beside each folder indicating how much of the drive it takes up. Xinorbis is freeware, Windows only. Thanks SanwariCethegus!