Blogs. Podcasts. Video-sharing sites. Social networks. Here's a word of advice for companies scrambling to become a part of these conversations. It's not enough to build a hub in Second Life or create a profile on MySpace.com (NWS ). It's time to shift your focus away from trying out every high-tech platform that comes across your in-box. Instead, home in on your customers. Almost every demographic group you can think of is engrossed in the Web these days, and users are getting smarter about their tools. It won't take long to find the consumers who care about what you're doing—and tune in to what they're doing. --BusinessWeek