In November 2002, HP released the iPAQ h5450, featuring the FingerChip AT77C101. This was the very first PDA with a built-in fingerprint sensor.
There were many reviews about this product on the Web... Here are two papers about it:
The Cogent bioengine performed the fingerprint recognition.
Some other software have used the FingerChip like Utimaco SafeGuard.
In 2003, HP released the h5550: similar to the h5450, the processor was upgraded as well as the RAM.
The iPAQ H5550 was also the base of the Tactical Communication D-DACT device, but the fingerprint sensor seems not having been used.