I came across this video the other day and HAD to buy this FP waves hem slip because of it.  I'm a firm believer in fashion that follows form and function and not only does this piece serve as an undergarment, it can also be worn as a dress, a tunic, a top, a beach cover up, and a slew of other variations.  Just watch!  It's incredibly well executed - which is to be expected from the boho geniuses at Free People.

Ways to Wear the Waves Hem Slip by Free People from FreePeople on Vimeo.