There are plenty of cup holders that can stick into the cushions of the the couch, but I wanted one to hang from the lamp behind the couch (still in arm's reach). This gives a place to hold the soda for the person sitting in the middle of the couch.

Since the hook is custom for my particular lamp, I've included an stl without the hook - so you can add your own attachment in the editor of you choice. The holes in the bottom aren't to reduce the plastic used, but to keep grunge from building up in the holder. (it also means it won't hold overflowing beverage - so user beware)