Do you remember when you first got that large hard disk and wondered how you would ever use all that space? Do you now wonder where it all went and why it no longer seems large enough? Filelight can help you answer that question.
Filelight is a KDE application that scans a directory, usually your home directory is run as a normal user, and displays a stacked pie chart showing which directories are using all the space. Move the mouse over a directory to see just how much space it is using, move over subdirectories to see what they use. Some of these will be expected, like a music, photo video directory, but you may be surprised how much has accumulated in other places. For example, if you have viewed a lot of photos in Konqueror or Dolphin, your .thumbnails directory contains, well, thumbnails of all of them, even photos you have long since deleted. Similarly, download, cache and temporary directories can build up without your realising how much.
Clicking on a directory makes that the new centre of the chart, or you can right click on it and open either a Konqueror or Konsole window at that directory, ready for further examination of just where all that space went. Freeing up space this way not only leaves more room for other things, it can also speed up your computer somewhat.