Use 'ls' to only show directories

Lifehaker has a great tip on how to use 'ls' to only show the subdirectories at the command prompt. When you know about it, it is kind of obvious (if you know some simple regexp), but a it is still very handy. 

So, what you do is to type

    ls -l | grep ^d

at the command prompt. This will only list your subdirectories.