If you are a Terminal user and like to explore and manage aspects of OS X using the command line, one convenient function is to be able to quickly access the current folder either in the Finder or in the Terminal. Sometimes navigating through folders can be easier in the Terminal, and at other times it can be easier in the Finder, but the problem comes when you try to combine the use of the two environments in the same task.
Finder to Terminal
Unfortunately the Finder does not have any built-in means to open the current location in the Terminal, but there are a couple of third-party utilities that have this functionality. One I commonly use is a freeware utility called ">cd to..." which will open the foremost Finder window in the Terminal. The utility can be placed in the Dock, but the most convenient location for it is in the Finder toolbar so it can be conveniently accessed from any Finder window.
Terminal to Finder
Though options for opening locations in the Terminal exist, people may not be aware of the option for going in the reverse direction, which is to open the current working directory in the Terminal in a Finder window. This is actually very easy to do, and makes use of OS X's built-in "open" command, which will open a file type or location using the default applications set in the system's Launch Services. When you are in the Terminal, just run the following command:
In this command, the "grave accent" characters surrounding the "pwd" command (they are not apostrophes) will run the pwd command first so the "open" command can then act on its results. The "pwd" command will output the full path to the "present working directory," and the "open" command will then open this directory in the Finder.
This command is useful especially when you are navigating through hidden directories using the Terminal. Unlike the Finder, which by default hides a number of files based on Finder-specific settings, this command can be used to quickly access these hidden directories. While navigation in this sense is more robust in the Terminal, sometimes using a GUI to manage files is a better option, and this is where this command comes in.
If you find you are using this command frequently, you can save it in a simple shell script and then save the script with a unique name to the /usr/bin/ directory. This will include the command in all other Terminal commands and allow you to quickly access it by just entering the script name at the command prompt.