In this verse, Peter is saying that ALL of us share the same faith. By this I mean that there is but one faith, not a whole bunch of faiths. Peter is pointing out that the only source of faith is God, its author. God gives the same faith to all. Peter is saying that all of us are the same in God's eyes. God doesn't play favorites,giving one person a different type of faith, or in differing amounts, than anyone else. Peter, Paul any of the disciples, or great men of faith throughout history were not given "extra" faith by God. The same Jesus that is the cornerstone of the faith of Peter is the cornerstone of the faith of you and I.
The only "difference" in the faith expressed by the spiritual "giants" and me is that my acceptance of, reliance on and devotion to the faith that I have been given is many times markedly less than theirs. While God gives the same faith to every person, not every person uses that faith in the same way. Much like you could give every person inthe world $100 and have virtually no two people use it in the exact same way. Some would save it against tragedy. Some would invest it in themselves, some in others. Some would simply squander it. So too with faith. SOme horde their faith, in case tragedy befalls them and they "need" God. Some use thier faith to enrich their lives, some the lives of those around them. Some squander their faith, and the faith they recieved at one time or another leaves no real impact in their lives or the world as a whole. I think that most of us, and I'm definately including myself, do all of these things, to one degree or another at different times and seasons of our lives.
Another difference, or disparity, in the "level" of faith exhibited by me in relation to a Peter, is that too often I let myself get in the way of my faith. Be it "intellect", concern over trivial matters, pride or whatever, many times there are things that prevent me from fully excersising the faith that I have been given. All too often I choose to lean on my own understanding, instead of trusting God.
The good news in this passage is that of hope. You see if God did indeed hand out differing levels of faith, or different kinds of faith, then I would have no hope of improving my Christian walk, of ever growing closer to God. But, since there is only one faith and it all depends on how we use what we've been given, I can "learn" how to more effectively live out my faith!