a guy in my class added 2 pockets in the back of his coat....looked awful but it worked for him
Be careful,
pack mule syndrome, as I call it, is not a sign of preparedness, its a sign of unsuredness. The more you have on you, the more you say "I can't handle what comes my way, so i need more to be prepared." I know many people will not agree with me, after seeing the ER attending with literally every tool in his pockets... But if you don't believe me, think about a resident that impressed you. Knew his patients without looking at a list. Confident with presentations, savy with patients. What did that person have on him? Probably a moleskin, a pen, and patient list.
That being said, there certain things that are essential to have.
You have got to have a pen or two (your resident may steal one), a stethoscope, some way to track patient data, and a pocket book to read. Beyond that, extra equipment just isn't necessary. Think about the tools you will actually be using, and see if they actually matter.
The reflex hammer, for example, is silly (unless you're on neuro). Every patient every time does not need a deep tendon reflex. Its thorough, but likely not relevant. Besides, the edge of the stethoscope works just fine for the knees.
You carry your own otoscope? They aren't on the wall? Do you actually do otoscopic exams on patients admitted to the hospital (like everyday on rounds)? If you want to be super cool, you could free up space in your white coat by having a holster (police officer mag-lite holster works well) on your waist. But honestly, lose the otoscope, you really don't need to lug it around.
My rig right now: two pens and my cell phone / epocrates on my breast, a moleskin behind pocket medicine on my right, stethoscope around my shoulders, and a free pocket on the left to accept whatever ridiculousness comes my way (such as carrying order sheets, to do lists, etc.). Occasionally, it has some candy bar or some other nutritional supplement.