Every chair should have a spot for a drink -

The reality is yes every chair or couch should have a spot to put a drink down while socializing in your home; but... what if you just don't have the space to do so?
It would be great if we all had the room for side tables,  a couple thoughts that I have to solve this space issue. Concrete blocks! I know it sound heavy but trust me, purchase a few from your local hardware store. Paint them a great funky fun color or wrap them in fabric (watch your toes). When you need the extra table for guests, stack them up next to the chair and you have an instant table. They are fairly easy to store under the chair, couch or even in a closet close by.
Another idea is extending the window sill to hold a drink ( if the chair is near a window).  Adding a piece of plywood or granite would provide you with a deeper surface. When not in use for drinks you can keep plants in the window.
Sometimes thinking outside the box will take you far and create a design that really functions for you.
Does anyone have any ideas to add?