Yesterday evening for giggles and grins I ate some expired peanut butter. Ah, but you say, that stuff is so chock full of preservatives that it's no mind! Ah ha, I say, but this was fancy no-preservative-bought-it-over-priced-at-
that-kind of store peanut butter.
While lying in bed nauseated as heck, it dawned on me how useful it would be to have detachable arms. I decided this was a brilliant plan* and I needed to jump on it immediately so that I could make millions and hire someone to eat bad peanut butter for me so I wouldn't have to do it for myself.
Just think! If you were at the doctor's and were afraid he'd diss you for your weight gain, you could just detach an arm or two before weigh in. You could do the same thing at Weight Watchers meetings.
You could take them off to squeeze though tight areas, or like when someone parks too close to you and you need to squeeze into your car door (or through their car window so you could take a dump on their driver's seat, not that anyone of us would do something so diabolical).
You could take one off so you could lie on your side more comfortable.

You could take one off to snuggle up closer to your sweetie.
You could take them off at night so when you slept funny wouldn't wake up with your arm asleep and all creepy feeling and your shoulder out of whack!
It was brilliant! What could go wrong with this business plan?
Then it dawned on me that if you detached both your arms you wouldn't have any arms left to put them back on with. Serious design flaw there. So, nevermind.
Oh yea, and some cards.
The Fine Print: *Well, of course I hadn't gotten around to all those niggling details like bones, and muscles, and veins, and arteries, and shit. That's why you hire a development committee to work around all that. Cards by Club Scrap Navajo, dude.