Here is a really cool one to work your upper chest. This is a good way to do incline negatives w/o a spotter. Start out by grabbing a couple of dumbells. Get into a position where only your shoulders are on the ball, and your hips are elevated. Mimicking a position of a flat bench. You then press the dumbells up over your chest, (just like a flat dumbell press.) Now, keeping the dumbells in the same spot, drop your hips till your body is in an incline position. From there, you do a slow negative, that stresses the upper pectoral region. After, you lower the weight, return to the flat position and repeat the process. The reason this works, is your chest has a leverage advatage in the flat position, thus making this movement possible.