I LOVE it. I'm not a fan of free programs like Mozy (I know it's not free for everyone, but most people I know with it are on some kind of freebie referral plan). The Sugarsync app has been rock solid and mobile access to my files is brilliant.
I posted a review of the beta back in February:
http://boardingarea.com/blogs/travel...iew-sugarsync/
FWIW; Pogue says that files on a Blackberry or Windows Mobile device are also backed up, which is not true AFAIK, access to backed up files is only available through the web browser on your PDA. The mobile client can only backup photos.