I have an N800 (as well as 770 ) and I'll admit I have an iPhone too. But neither is quite the perfect device. I'll also admit I am interested in the Foleo from a conceptual point of view, but the hardware is way off base. So for me, it seems the "perfect" device would combine elements of all three of these.

First, the only contribution of the Foleo - the idea of a smart phone companion. But make it a dumb phone companion instead. All I need a phone for is making/receiving calls and using cell network when WIFI is not available. (N800 would have this if it had decent PDA/mail).

Next, the iPhone. From it I'd take the form factor, browser and keyboard, with it's 'smart' correction and it's touch screen - much nicer than N800's. The PDA functions and mail are nice too, but they'd need to be more open to integrate with more backends.

From the N800, pretty much everything else. It's mostly open OS, WIFI, BT ( w/keyboard and GPS support ) , screen, VOIP/video conf support and multi-media support are great ( and getting better ), plus the dual SD slots for expansion. Ok, maybe take the iPhone's camera; it's nothing to write home about but better than N800's. Add USB charging and USB host mode.

What about you?

How about the Toshiba G900? It has 3G HSDPA and a 800x480 display.

Unlocked G900

TOSHIBA PROTEGE G900 HSDPA TRIBAND MOBILE PHONE
TOSHIBA G900 MOBILE PHONE

Operating System Microsoft® Windows Mobile® 6.0 with Direct Push technology
GSM/GPRS Tri-band 900/1800/1900MHz, HSDPA, 3G, EDGE
Bluetooth Yes
Camera 2 Mega-Pixel
Memory Card MiniSD
GSM Band 900/1800/1900
• 3G availability Yes
• GPRS class Class 10
• EDGE (Yes/No) Yes
• HSDPA (Yes/No) Yes
• Wi-Fi (Yes/No) Yes
• UMA (Yes/No) No
• Main display resolution (X x Y pixels) 800 x 480
• QWERTY keypad Yes
• Touchscreen for Main display Yes
• Camera hardkeys Yes
• Main camera resolution (in XX MP) 2MP
• Flash (Yes/No) Yes
• 2nd camera (Yes/No/Rotate) Yes
• 2nd camera resolution (in XX MP) 0.3MP
• End User memory size (MB) 40MB
• Bluetooth version v2.0 + EDR
• BT Music stereo headset profile A2DP Yes
• BT Music stereo headset profile AVRCP Yes

Screen is only 3 inches and at 800x480. Text will be very small. Images should be excellent however.
Priced at over 700 USD.

Definately not.

My perfect device has to be less than $500 and have a screen between 3.5 and 4 inches. Phone not necessary.