The HP site also says the GSM/GPRS Wireless pack is "Coming Soon":
http://h20022.www2.hp.com/busprod/po...debarLayId=823
But that's been coming soon for 2 years.

Although now it lists the 5400 as being compatible, which we already know it ISN'T compatible with the current version... must be a Wireless pack software update in the works.
The cell phone buttons on that keyboard would work with an iPAQ H5600 Phone Edition... if those models were actually ever going to be produced or released. Maybe they still will??
And.. that keyboard won't work with the 2200 series, and the flip screen is removable I'm sure. Maybe George M, can modify this thumb keyboard expansion pack to also have a silver slider style Compact Flash slot. Hmmm.