how to find out and delete these files?

Is there any way to find out what's taking up most of my hard drive on my MBP? I have opened the Finder and selected All My Files and sort by Size and there's no more than a few gigs of files that show up there. 172.75GB is being taken up by "Other." Does anyone have any idea what "Other" could be or how I can find out specifically what is "Other"?

Sorry if this is in the wrong place this is my first post.

Take a look at this blog post.

Thanks that did the job, Now i got some cleaning to do..