Fring is a mobile service that provides VoIP and chat services for Windows Mobile and Symbian-based mobile phones. Today, Fring releases two new versions, JavaME and Linux.
Whilst I do not have the Nokia N800 or N810, I will have to test this on the N770 and see if it will work. Fingers crossed. :)
Unfortunately, the iPhone support is only for jailbroken iPhones and not for the newer iPhone 2.0 firmware-based iPhones.
So, do you Fring?