OmniDiskSweeper for Mac
 

Son was visiting Apple Store in London wit iPhone query, and somehow the conversation turned to iMac the rep recommended this:

OmniDiskSweeper for Mac

OmniDiskSweeper for Mac - Free download and software reviews - CNET Download.com

Any comments

PZU - Out of Africa (Retired)

Perhaps if you were having problems with space on your iMac internal drive this might be helpful. I've never maxed out my drive, nor have come that close.

Just under 200gb of 500gb at the moment.

I'd be tempted to use the built-in Spotlight, or Finder, search engines first before getting yet another 3rd party application.

It's always useful to be able to see what's taking up space on your hard drive. Spotlight doesn't give an easy to see graphical view of the drive. This one's a favourite with us Mac users:
http://grandperspectiv.sourceforge.net

DiskSweeper is a marvellous tool, but it is very sharp - it is easy to delete files that have basic functions in your computer.

But it has a marvellous way of displaying absolutely everything that is on your hard drive, layer by layer, and can find anything - which Spotlight can sometimes miss.