The nature of trends is to die out-especially on television. So last Earth Day, I was amazed to see Captain Planet, the star of the 1990s TV series "Captain Planet and the Planeteers," trending worldwide on Twitter. Don't get me wrong-I love Cap. He was one of my favorite "stars" to work with when I was vice president of PR at Turner Broadcasting. After all, he had great hair (how could you not love that green mullet?), a catchy theme song, and a message you could really get behind-and not just because it was my job.