I spent some time today with Palm's not-yet-released Foleo at the LinuxWorld conference here in San Francisco. Due out this summer, the $600 not-quite-a-laptop device is small and light and might be of interest for some Treo-using mobile professionals, but most people would likely be much better served by a regular notebook.

Click for a larger image.
The Foleo is the first Linux-based item from Palm, and touts an easy one-button e-mail sync over Bluetooth with Treo smarthones (both Palm OS and Windows Mobile versions). It has a 416Mhz processor, 256MB of flash memory and 128MB of ram, but no hard drive. The 10.2 inch screen has a 1024x600 resolution, and it has 802.11b and Bluetooth 1.2 wireless capabilities.
There's a single USB port, along with slots that can accept SD or compact flash memory cards (Palm says they've tested cards up to 4GB). And you can connect the Foleo to an external display, which will use a 1024x768 resolution.
As the Palm guys at the conference put it, the Foleo is meant to be "what happens when a PDA grows up," rather than a shrunk-down laptop. The applications are similar in look and feel to what you'd use on a smartphone, but are of course easier to use with the larger screen and full-size keyboard.

But the Foleo is far more limited than any given smartphone in terms of programs. It has 14 programs, including a basic word processor from Dataviz, a Palm calendar and mail program, and a Web browser based on Opera 9.
The browser supports Flash 7, but not Flash video. And you don't get Opera's tabbed browsing. Here's a screen shot taken on the Foleo and e-mailed:

Click for the full-size image as it appears on the Foleo.
The problem is that you can't use the large array of Palm OS or Windows Mobile apps on a Foleo, unless the company or person who wrote the app reworks it for the new device.
And you likewise won't be able to use Linux apps unless someone reworks them for the Foleo. The device uses a Linux kernel (2.4 now, 2.6 is coming) but has a custom GUI interface that means more work than a simple re-compile to get an app to work.
Palm plans to release a software developer's kit to make this re-development possible for Treo and Linux apps, and some companies are already using it to get their games and remote desktop utilities ready.
Astraware has solitaire and sudoku games ready, and LogMeIn is working on a browser client that will allow you to use its remote desktop access to connect to a desktop from the Foleo. But I have to wonder just how many programs will actually become available in the long run.
At 2.5 pounds, the Foleo is a good deal lighter than most laptops. And it does appear to be a simple, ready-to-go option for working with your smartphone's e-mail or performing basic tasks. It's also easy to use your Treo as a Bluetooth modem for Internet access in places with no wireless, though you'd need to check with your service provider to see what their policy is on such access.
But for $600 ($500 with a $100 mail-in-rebate), I'd hunt around for a used laptop, especially if I already had anywhere-access with my Treo. I settle for a limited selection of limited-function apps on a smartphone as a trade-off for it fitting in my pocket. If I'm going to have to carry something around, it may as well be a laptop.