For those of us in the entertainment industry, a teleprompter is a godsend, at least for certain projects. It means we don't have to sit for days memorizing scads of technical information for an industrial film about some science and technology product. I have filmed many, and I can tell you it takes a huge pressure off knowing that the dialogue will be available to you, and that you don't have to rely on your feeble memory to come up with technological terms you've never heard of. But, there is definitely a skill to reading a teleprompter well; they aren't that simple to use, and it takes practice to make it look natural. Obama has it down to an art. McCain doesn't.
Let's face it, Obama is a magnificent orator, as long as he is on teleprompter, but the following short video shows what happens when he loses track. It just demonstrates his flair for speechifying is only as good as his speechwriter, his teleprompter, and whoever happens to be running it.