Apple said it has seen more than 6 million users download and install the recently-released 3.0 software, but new data from AdMob suggest iPod Touch owners are not making the leap as quickly as iPhone users.

AdMob said just 1% of iPod Touch owners have downloaded and installed the latest firmware, compared to about 44% of iPhone owners. The data is not comprehensive because it is based on apps that tie into AdMob's mobile advertising network, but it does give a solid indication on how quickly iPhone and iPod Touch owners are adopting the new software.

The 3.0 firmware adds a host of new features for iPhone and iPod Touch users, including the ability to cut and paste, improved podcast controls, and the "shake-to-shuffle" music playback feature. But many industry watchers see developers as the main beneficiaries of the firmware upgrade because content creators have been given more than 1,000 new hooks into the hardware, and they can implement features such as push-notification, in-app purchasing, and peer-to-peer gaming.

One of the reasons iPod Touch owners may not be upgrading is that they have to pay a $10 fee, while iPhone owners get it for free. Apple said it is required to charge iPod Touch owners due to government-imposed accounting practices.

"The additional $10 fee is clearly limiting uptake," AdMob said in a blog post. "Developers looking to sell applications utilizing the 3.0 feature can't be happy with Apple's decision to charge for the upgrade as it limits their available market size for downloads."

Apple is likely to show off the next generation of iPod Touch devices in September, and those personal media players should come preloaded with the 3.0 software.

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