Handspring

From TreoCentral

Handspring is the company that invented the Treo Smartphone. It was founded by Jeff Hawkins and Donna Dubinsky following some internal head-butting at Palm (then owned by US Robotics). The history of Handspring, first breaking away from Palm and then finally being purchased by them, is a complex one that needs to get filled out here a bit more.

Briefly, however, it's worth noting that Handspring's first product was the Visor and that it was designed from the start with the VisorPhone in mind. Likely the Treo itself was not far from their minds from the start.