. . .
Can anyone tell me why it is using so much space there?
That may or may not be excessive. See Lion's Storage Display.
This is one thing I really don't like so far, when you uninstall a program it leaves behind a bunch of files.
If the app came with an installer, see if it has an uninstaller (oddly, it may be an option in the installer). Some do, some don't, but most of the ones that do will uninstall the other files, too.
There are some 3rd-party apps that try to remove such files, such as AppZapper.
I would love to know how to quickly and easily free up as much space as possible.
After reviewing the link above, if you still think there's unexplained space, there's a link to Where did my Disk Space go?
I have a new MacBook Air with a 256GB SSD. After loading the normal applications, I now have 132GB of "Other". I am seeing that other people have the same problem... but not 132GB! It seems a little extreme. I can barely load a new application... I am almost out of disk space.
Is AppZapper reliable? Are there any other suggestions on how to get rid of "Other"?