Nielsen's mobile web statics show that, from July 2008 to July 2009, the demographic groups of 65+, female and 13-17 showed the most usage growth. The least? 18-24 year olds, who are all up in this mobile web already.
Also equally interesting: we have a higher percentage of male readers than the NFL, the NBA or even MAXIM. More women look at softcore boobies than look at gadgets! [Nielsen]