Steve Wozniak was the main inventor along with help from Steve Jobs and Ronald Wayne.
Apple
Jonny Ives, Apple's chief designer was the main person in charge of the look and feel of the iPad, but Steve Jobs was the person who made the decision to build it.
The main difference between the iPad 1 and 2 is that the iPad 2 is thinner and lighter than the iPad 1. The iPad 2 is also faster than the first iPad and the iPad 2 has front and rear cameras.
The iPad 3 is rumored to be different than the iPad 2. The main differences are a better quality screen and pricing differences.
no
The IPad in 3g is a slower, older version while the IPad 2 is the newer, faster, sleeker tablet from the Apple corporation. The IPad 2 is more expensive though.
there is only one button...
Graphics speed and resolution, and the camera.
Steve Jobs, Steve Wozniak, and Ronald Wayne were the main people.
Steve Jobs & Steve Wozinak
What your phone system says when it can't get through is not the fault of the iPad. Skype and other IP phone systems are separate from the main phone switchboard, so you may need to just sleep your iPad instead of turning it off to get the app to work.