Recently I lost my N82 (and have since bought a 5800 XM). I wanted to let some of my contacts know of my loss, but even though I'd synced with PC Suite there's no way to get at those contacts on the desktop!
Recently I learned you can sync "to the cloud" by using Ovi.com, so I've set it up on my 5800. It wasn't obvious, so here are the crucial steps. Visit Ovi.com and follow their instructions for selecting a device, getting an SMS sent to it, confirming a PIN number and saving the settings. All good to there, but then what?
Go to: Menu > Settings > Connectivity > Data Transfer > Sync
Within 'Sync', you have to use 'Options - Change active sync profile', and then select Ovi.com instead of PC Suite. Finally, Options > Synchronize.
Now my data is safely in the cloud! This service is similar to that offered by Apple's MobileMe.