You can also go from the two arm push-ups to the diamond pushups which target mainly your triceps. It gets you use to the form of your arm going down to the floor and back up as doing one arm pushups do. Only difference is your are using two arms, but you take that one arm away and you will see how diffucult it really is. lol. If you dont know what a diamond pushup is just place your hands together on the floor in front of your face, not out to the side like a bench press pushup. Connect your thumbs and index fingers to where they are touching one another to make a somewhat diamond shape with your hands. Then go down and push your way back up. After you get use to them, try getting the tip of your nose into the middle of the hole/diamond shape you create with your hands.

Just a different technique. Have fun.