Sales of smart phones are expected to overtake those of laptops in the next 12 to 18 months as the mobile phone completes its transition from voice communications device to multimedia computer.

Convergence has been the Holy Grail for mobile phone makers, software and hardware partners, as well as consumers, for more than a decade. And for the first time the rhetoric of companies like Nokia, Samsung and Motorola, who have boasted of putting a multimedia computer in your pocket, no longer seems far-fetched. "Converged devices are always with you and always connected," said Olli-Pekka Kallasvuo, Nokia Chief Executive at Mobile World Congress in Barcelona. Last year Nokia sold almost 200m camera phones and about 146m music phones, making it the world's biggest seller of digital cameras and MP3 players. In the coming year the firm predicts it will sell 35 million GPS-enabled phones, as personal navigation becomes the latest feature to be assimilated into the mobile phone.