The answer is simply, Yes. Scoring is possible on current versions of both an iPhone or Blackberry. Due to the small screen size, scoring on an hand-held device like an iPhone isn't always as pleasant as scoring on a laptop or even an iPad, but it is possible.
There is a pdf tutorial on iPhone scoring HERE.

Or there is a short video tutorial on scoring with an iPad HERE
Stay tuned for further developments on mobile scoring options on Regatta Network.