This is surprisingly a very viable option, particularly for young wines. The amount of oxygen your wine absorbs is not really governed by whether the bottle is corked or not. There is more oxygen in the headspace (the empty part of the bottle) than your wine is able to absorb over night, so corking the wine does little in that respect. It does keep flies and debris out though, so I always recommend corking up your bottles for the next day.
What does govern the rate of oxygen absorption? Surface area. The greater the surface area exposed to oxygen, the higher the rate of absorption.
So putting a cork in the bottle and leaving it out on the counter is not a terrible way to treat your wine, particularly with younger wines that can use some softening and evolution in the bottle. Still, it’s not the best way.
Photo courtesy cbcastro via Flickr/CC