I’ve been too lazy (or too preoccupied, maybe) to look this up for quite some time. This one-liner comes in handy if you are in a terminal window and need to view the files in the current directory in Finder. For instance if you needed to take a look at the graphics in a folder.
open -a Finder .
This could be applied to any application. For instance:
open -a 'Google Chrome' .
open -a Terminal .