Mobile phone users around the world spent $400 mln on pornographic pictures and video in 2004, an amount that is expected to rise to $5 bln by 2010, despite the tiny screen sizes, according to an updated estimate from Strategy Analytics. The $5 bln in porn revenues by 2010 is $4 bln more than Strategy Analytics and Juniper Research had forecast until recently. It has upgraded its estimates, because adult entertainment businesses are aggressively building services, and customers are buying.