Ok so at the beginning of this thread,(before it became a pissing contest)...ChinPieceDave667 said you cant work your chest in "parts"...that is total bullshit. Yes, when you try to isolate a portion of you chest you still work the whole pec, however you work different fibers. Going with the logic of not being able to work "parts" of a muscle would be the same as saying, wide grip preacher curls and close grip preacher curls work the bicep the same way. However, wide grip increases the thickness(width) of the muscle while close grip increases the peak(height). So, I call bullshit.

If you wanna work upper-chest, do incline(30-40 degrees) dumbbell presses and flies. Presses will make the muscle thicker, and flies will make them more defined. Also, do cables. Start cable low, then raise it up, across your body ending level with your head and on the opposite side of the body from starting position, then slowly lower it back. that has been the most effective lift for me.

I know this question was posted a while back, but the poor knowledge of anatomy and how muscles work aggravates me. Good luck!