With more than 2.2 million cell phone users in the world today, the industry is always buzzing about the "killer app" for Mobile. Well, News.com reports that outgoing Nokia CEO Jorma Ollila may just have an answer, and an obvious one at that. Forget camera phones and handsets with music players, in his keynote speech yesterday, Ollila said good old voice calls are still number one. "Mobile voice is still the killer application," he said. "Subscriber growth is still fueled by voice, and voice will be the most valuable form of communication for a long time still. There is still much work to do to improve voice connections and handsets." I couldn't agree with him more.