Consequences of converting an S-Corp to a C-Corp

I'm trying to decide whether to to incorporate my company as a C-Corp or an S-Corp. I've got a very successful iOS app bringing in substantial revenue already, and I'd like to start hiring a few other developers to expand the app and develop a sequel. It sounds like a C-Corp is what I'm aiming for in the long term, but an S-Corp sounds more ideal in the short term.

It's been implied to me that it's possible to start as an S-Corp for a while, and then become a C-Corp if and when we start looking for investors.

I'm wondering, what are the consequences of such a move? Upon converting the S to a C, would it work exactly as if it had been a C-Corp all along? Or would there be some lasting impact, positive or negative, from having spent some time as an S-Corp?