http://www.cyberciti.biz/faq/linux-list-just-directories-or-directory-names/
Well done again cyberciti. Excellent solution
As it says on the link, add these to ~/.bash_profile
alias lf="ls -l | egrep -v '^d'"
alias ldir="ls -l | egrep '^d'"
Then (article aught to remind you of this) bring it to life with . ~/.bash_profile