Online Portfolios.... Possibly?????

As my graduate cohort's portfolio display is fast approaching, I have begun to think about the potential for this as a "final exam" style activity for high school students. The SOL tests that are administered in May of each school year now, have become the defacto 'finals' that students genuinely prepare for. And many educators lament the task of trying to "review & prepare" students for another large test/exam right on the heels of the SOL tests. So, my question is, given the relatively open access to computers and the internet to high school students, would a web published 'portfolio' of yearlong learning displays be possible in most core subjects? And if not, what barriers are most likely preventing it? (Technology 'barriers' or Human "barriers' or a combination of both?)