I just found this and thought I'd share. I wrote up a Knowledge Base article on this too: http://software.intel.com/en-us/articles/mac-os-x-tip-how-to-make-opt-visible-in-finder/
Introduction: Intel Developer
Products tools such as compilers and libraries install by default in
folder /opt. Unfortunately, by default Finder on many versions of Mac
OS X hides the /opt folder, that is, it does not show the /opt folder
and subdirectories by default.
This can be annoying because Intel installs the HTML documentation along with the product under /opt/intel/...
Making /opt Visible in Finder:
The following command will make /opt and it's subfolders visible and navigateable under Finder:
sudo SetFile -a v /opt
After this, open or re-open a Finder window and /opt and it's subfolders should be visible under Finder. This allows one to quickly navigate to the Documentation folder.