Again, under the current law, the IRS will not be penalizing you in any way for not paying the "I Don't Want Insurance" tax. Here's my WalletPop column about the mandates.
Via Oliver Willis, here's IRS Commissioner Douglas Shulman talking with Representative Ron Kind in the House Ways & Means committee:
Of course, if too many people try to stick it to the man, they'll probably change the law and begin to enforce payment of the tax.