Mac: DockPlay buttons for Spotify and iTunes are very simple programs that can play, pause, and go to the previous or next tracks directly from your dock while the music player runs in the background.
All you have to do is download the zip file, add the three separate controls to your dock, and fire up iTunes or Spotify.
The question you must ask yourself is which is more annoying: having to switch from whatever you're working on to your music player to skip a track or losing three icons worth of space in your dock? That will determine for you if this simple hack is worthwhile or not.
DockPlay is a free download for iTunes or Spotify. The download page at the link below is work-safe, but other parts of the site have NSFW content.