I have own these keyboard for year and use they with various Palms . I will continue to use and recommend they to other for every handheld except the iPaq 3900 series .  the iPaq keyboard interface be design for the prior ipaq series , so you must use a adapter to use the keyboard with the 3900 . the adapter be carry separately and will be easily lose . in addition , the adapter raise the iPaq up about 1\/2 inch higher off of the keyboard than the original design . it look a bit unsafe and feel like the iPaq be go to flip off the back of the keyboard . remember , the iPaq be a bit taller and heavier than the average bear .  the adapter be also difficult to force into the end of the iPaq to begin with . the adapter have no guide keep it straight during the delicate journey into the nether region of the handheld , and it be a tight fit . I have to jiggle the adapter sideways until it settle into place , and I be sure I would take great care in perform the maneuver in the future , although that will not happen . this be really a shame because one great advantage of the Stowaway be the fact that it can be break down and put away in seconds -- wonderful when you be do research in a library and do not want to walk away from you computer . ruefully , it be not the case for the newer ipaq owner in the crowd .  I have the keyboard for about 30 minute before I return it . I think they be great keyboard , and think outside be a really good company . however , the company need to commit to a real interface design for newer ipaq owner . sadly , I have to say save you money and wait for something better to come from this company . maybe they 'll put out the XT version for the iPaq in the near future . there be always hope .