In any event, I'd be surprised if the Nokia backup that is in the Control Panel wouldn't work. That is, I think it would work fine. I've never done it between two different devices, but it only makes sense that it would work since it re-downloads and re-installs everything. The backup will be put on the N800's SD card automatically. Then just put that SD card into the N810, use Backup's Restore feature, and browse to that back-up on the SD card. I bet it will work fine.