Palm's new Foleo smartphone companion has received the thumbs down from industry experts, with Gartner describing the gadget as "offering too little functionality to justify the burden of carrying around another device".

The 1.14Kg unit, which synchronises with a smartphone via Bluetooth, has a full keyboard and 10in display.

The Linux-based system is designed to enable users more easily to work on email and documents residing on the smartphone as changes made on the Foleo are automatically reflected on the connected phone, and vice versa.

Gartner analyst Todd Kort noted that, in an era in which increasing functionality is converging into ever-smaller devices, Palm has decided to buck the trend.

"The Foleo is too large for many smartphone users to consider carrying around as a limited-function accessory that requires a separate carrying case," he said.

"Gartner believes that this unwieldiness will severely limit Foleo adoption by smartphone users who place a premium on 'pocketability' and attractive design.

"There is a small but growing segment of the market that would welcome a low-cost device with a full keyboard and good display that is capable of roughly 75 per cent of what most notebook computers are used for. But the Foleo falls short of this."

Kort added that the Foleo could be more successful if it were modified and repositioned to serve as a low-end Linux notebook PC capable of replacing full-blown notebooks in basic usage situations.

"The Linux community might rally behind a more capable device with a faster processor, more memory and a larger battery," he said.

Palm, however, argues that the Foleo is not intended to serve as a notebook replacement, but as a companion product that enables a smartphone to function more like a PC.

Foleo will be priced at $499 after an introductory $100 rebate, and will be available in the US late in the second quarter.