I always ran out of space regardless of my HDD size! so I often delete stuff I don’t need anymore. Today I was doing the exact same thing and as always I came across a big Zip file I have no idea what is inside. So I looked around for a cool plugin to add this functionality to Finder’s Quick Look. Now all I have to do is pressing SPACE while the mystery zip file is selected in Finder.

Now how to install this plugin:

1. Download it from here (it’s called Archive.qlgenerator)
2. Navigate to  /Library/QuickLook/ or ~/Library/QuickLook/
   Lion users: you can’t see your root folder anymore, just type open /Library/QuickLook/ in Terminal
3. Copy Archive.qlgenerator there
4. Restart Finder.app (Right click Dock Finder icon with holding Option key)
5. Just press SPACE to see inside any zip files.