When you work with the interactive shell, there’s a common pattern that is used a lot: Copying or moving files to a directory and then changing to the target directory using cd. In these cases, you find yourself typing the name twice:
$ cp file1 file2 file3 /very/long/path/name $ cd /very/long/path/name
Tab completion helps, but for long names it’s still tedious.
One of my favourite tools, the bash function g (“go”), shortens this to the following:
$ cp file1 file2 file3 /very/long/path/name $ g
It works by getting the previous command from the bash history, treating the last argument as a directory and then going there. If the last argument is a file name, the g function tries to resolve it to a directory name by using the basename or stripping off common archiver suffixes like tar, tar.gz or zip.
The function is one of the most executed commands in my shell history. I also had a companion function which changed back to the previous directory, but since cd - is pretty short, too, it didn’t get used that often. To use it, download the function and simply copy it into your ~/.bashrc file.
Note that this function works on bash only. I used to have a Korn shell compatible function, but it didn’t work as nicely as this one.
Matthias Friedrich's Blog 
Very nice command — I’ll have to use it in my bash scripts.
I usually use built-in bash facilities for this:
“cd !:$” will do the same (and !:$ ist just Shift-1.4 on a German keyboard, not as weird to type as it looks :-) !:$ meaning the last word of the previous line, also works with !:0, !:1, !:2 etc.
You can also use “cd “. Meta-. cycles through the respective last words of the lines in your history.
Whoops, WordPress ate some special characters in my last command. The command in the last sentence is meant to be “cd M-.”, where M-. is pressing Meta and the dot “.”.
I knew the Meta-. shortcut, but not back then when I wrote the “g” function, to be honest :)
There are a few reasons why I still prefer “g”: a) I can’t get the Meta-. shortcut working in vi mode. b) “g” is very short to type and creating an alias for “cd !:$” doesn’t work. c) “g” also changes into extracted tarballs and the like.
I might switch back to emacs mode soon, but b) is currently a show stopper for me. You don’t happen to have an idea how to solve this? I’m always happy to throw away unneeded code ;-)