American culture does indeed value individualism and has since the beginning of its history. Though the use of the concept of nonconformity in mass marketing campaigns can evoke vitriolic loathing by the masses who value true nonconformity, let us not contaminate the truth of individualism by focusing on its corruption.
My beef is largely semantic. Conformity does not mean getting your ideas from outside sources (impossible to avoid). Conversely, nonconformity does not necessarily mean rejecting any commonly held belief (ludicrously impractical).
Conformity is like art, it's about the process not the product.
An act of conformity is a decision to act a certain way in order to satisfy the expectations of a certain group. To some extent this is necessary to facilitate our worldly existence. To judge an act of conformity as either positive or negative, however, requires deeper analysis. Is the subject conforming for conformity's sake, or because they have legitimate personal reasons? The real negative connotation of conformity comes from individuals who need no deeper reason than 'it was on MTV.' In reality I believe there are always deeper reasons for everybody, but they can only be determined for oneself.
So is individualism an act of conformity? That depends on your own culture. In America it could certainly be considered conformist, but Americans should be thankful that individualism is embedded in society, rather than spiteful that their desire to be an individual does not make them unique. Anyone who thinks this way wants to be rejected by society for reasons that have little to do with individualism and more to do with twisted ideas about what society represents. If the goal of nonconformity is to live life on one's own terms, then a societal norm of individualism makes life a hell of a lot easier. If the goal is to shock and perturb people then perhaps a religious fundamentalist culture is more appropriate, but be aware the penalty for nonconformity may be death.