According to industry analyst Nielsen Mobile, the number of US women using smartphones doubled last year to 10.4 million – a faster growth rate than for men – while one-in-three iPhone purchases is female.

MocoNews points out that women are also using their smartphone more for pleasure than business, and refers to a claim by Verizon Wireless that 71 per cent of women make the decision about which operator, tariff and handset their family members use.

Implications for the mobile games industry? While it might be cool developing a whizzy 3D first-person shooter to iPhone, the big market for iPhone games is more likely to be in titles appealing equally to both sexes.

That's not a new idea, of course. Research from firms like M:Metrics continually proves that women make up at least half of mobile game purchasers. But many games developers still see smartphones as 'male' devices.

What the Nielsen stats don't prove, I think, is that developers should rush to create deliberately 'girly' games for iPhone and other smartphone platforms.

In a recent interview on CasualGaming.biz, THQ Wireless' James Scalpello described such titles as "a lost cause" on mobile, saying, "I don't think there's ever been a successful game really pinpointed just for girls."

There's clearly a lucrative market in games for actual girls, as opposed to women – someone must be buying all the pony games cluttering up the DS shelves, after all – but for smartphone platforms the opportunity is more about creating casual games that don't alienate either gender.