I've always hated it when there is no room for an end table, or heck, when there just isn't a place to set your drink. So after designing my Mountable Gear Shaped Cup Holders http://www.thingiverse.com/thing:2235067 for my arcade cabinet I decided that a double swing arm design would be handy for next to the bed, next to the computer, on the wall next to the bath tub... or wherever! I stuck with the gear shape, cause I love gears (I used my business logo for the shape). The images are currently of a draft mode print of the prototype, I am printing a much more solid / functional / updated version right now, I'll update the pics as soon as it's done.
UPDATE:
Added the new pic, I stopped the print before it put the top layers on the gear because I was digging the look of the infill. They are surprisingly solid at the higher resolution print settings with a more solid infill. I ended up going with bolts, the 3d printed pins were extremely easy to break. I spray painted the finished parts with hammerite for a sort of metallic look. Also, I found that with the right bolts and nuts, it can hold a 22oz beer (with the parts printed at maximum length).

I've designed some Pins for the mount holes, you are probably better off using actual bolts with nuts for the connections, but if your like me and are too lazy to go to the store for bolts, there are the pins for now. If you print the connection pins at a high resolution with a fairly solid infill they should, hopefully, maybe, might possibly, work?
EDIT: Nope, the 3d printed pins absolutely did not work. I went to the hardware store and just found some bolts long enough along with some washers and lock nuts. The bolts were 1/4-20 x 2-1/2...

I added 150mm arms in addition to the 219mm arms, so how long you want it to be is up to you and your print bed size.

As always, I hope you guys like it and maybe someone else will find it useful. Please post pics of your makes, I love seeing if others actually decided to make something I designed ;)

Update:
I added a couple of new cup holder types and a phone / tablet arm

"cause if they don't find you handsome, they should at least find you handy!" -Red