Entreprenurial Energy

Currently I'm studying internet marketing, using websites/blogs to enhance your business and launching new companies. I'm of the philosophy that it's better to jump in and figure out how to swim when you're in the water rather than wasting too much time planning your strategy and never getting your feet wet. What do you think? I'd love to hear your experience or opinions. Do you have a business that's enhanced with Twitter, a blog, website and/or forum? Do you give preference to businesses that are integrated in all these ways? Or is it just extra junk without substance?