Palm’s announced a new accessory, an instant-on ‘companion product’ for Treos and other smartphones to ship this summer. This is basically a sound approach; King Gillette demonstrated it’s easier to get rich from selling blades, not razors, and with the installed base of millions of Treos out there, accessories are viable. It also reaches out to those of us waiting, and waiting, for laptops to boot, with instant-on capability.

“Folēo” is a solid-state Linux micro-notebook with internal WiFi, and connects by Bluetooth to a Treo or other smartphone for synchronization, file sharing and cellular data connectivity. The 10″ screen (1024×600) and full QWERTY, ISO-standard 18mm pitch keyboard are far more humane ways to view and enter data than on a 2” screen and micro-mini keypad. VGA (1024×768) output’s included, as is access to applications popular on the Palm like viewing PDFs, editing Office files with Documents to Go, and the Opera web browser, as well as ssh and other Linux utilities near and dear to the hearts of sysadmins.

Palm founder Jeff Hawkins, in a presentation to the Wall Street Journal D: All Things Digital conference today, said “Pretty much anything a personal computer can do, you could do on a smartphone,” but a large screen and full keyboard’s often necessary. The product had been conceived five years ago, he said, (and he’d been hinting about it for quite some time,) but Palm had to wait for critical mass in the marketplace. He added 24 million people get e-mail on smartphone today, and that’s due to grow by a factor of eight in the next few years.

The webcast showed instant-on capability with very rapid task switching to e-mail, with quick scrolling and changes between display modes (zooming in to one e-mail only). The scroll wheel between mouse buttons controls movement and window switches, and with rapid moves, jumps from line-at-a-time to page-at-a-time scrolling.

The $599 Folēo (with $100 introductory discount) will weigh in at under 2.5 lbs in a 0.94” slim, 6.67” deep, 10.55” wide form factor. Five hours use on the internal battery was claimed. Slots for USB, SD and CF (the latter internal only) supplement the internal 256MB of Flash RAM. Windows Mobile devices will be supported out of the box as will Palm, and Symbian support is planned. The device will work without a smartphone, although Palm did show the Folēo unlocked sans password when a designated Treo’s within Bluetooth range.

Availability? SDK? Palm did not provide dates beyond ‘summer’.

Other solid state micro-notebooks have shipped, and failed, before, but flash RAM’s far faster now, and the synergy of WiFi and cellular connectivity may make the product click at long last. Will instant-on be your killer app? Or, will easy tethering through your smartphone induce you to choose a slower micro-notebook? Join the discussion.