recent house tour in the East Village of New York, I was impressed with the way the owners made use of their space. Next to a chair where there was no room for a side table, Michelle and Howard simply installed a cup holder on the wall. Not only was this a clever use of space, but it's also a light hearted addition to the look of the room.
If the concept of adding a place to set your cup is appealing but the commitment of a wall mounted unit is not, a similar effect can be achieved with a clip on cupholder.
An item that would be useful indoors or out, cup holders that clip onto chair arms are inexpensive and come in a variety of colors.
Find it on Amazon.