Oh, those triceps. They're a trouble-spot, aren't they? For most people (say, um, writers for example -- who sit at their computers all day long), the tricep isn't used too much in regular activity. So, without specific exercises to keep those muscles toned, things can get a little extra jiggly there. Shape Magazine has a great exercise for getting that under-arm jiggle under control.

To perform this exercise you'll need a foam roller. A quick internet search will give you many sites that sell these versatile and inexpensive pieces of fitness equipment. You'll sit on the floor with your feet extended in front of you. Place your hands on the foam roller behind you, with your fingers pointing forward. Then pull your rear end off the floor by pulling in your abs and straightening your arms (but don't lock your elbows). Bend your elbows until your rear almost hits the floor and then straighten. Repeat 8-10 times. Do 3 or 4 sets.

Want more exercises for the under-arm area? Chris has a suggestion you can try, too. And AOL Health has a step-by-step arm exercises guide.