yeah, going to the last directory would be
You can also have a directory stack (a list of directories), and be able to access lots of directories without having to type the whole path every time.
pushd ~ #sends your home dir to the dir stack
pushd #goes to the sent dir (home)
pushd #goes back
pushd /etc/somedir/ #now you have 3 dirs in the stack
pushd +2 #goes home again
etc. Depending on your shell, you can also go to the previous command using Ctrl-P btw. Which is a bit faster than pressing the arrow keys.