Suggestions for home NAS backup software, please?

Can you please recommend some good software for automated backup of home systems to a NAS?

Disaster recovery is not a major issue, since I keep image backups of the system disks of my home machines (if this software can do that, so much the better). Most important to me is having copies of all the documents and Email that my family creates, so that when they lose something I can get it back. Right now, I have to go to each machine and run my old backup software (does anyone remember Backup MyPC from Stomp?), and that doesn't happen often.

It would be an additional plus if this software could back up Microsoft Outlook folders intelligently. My software backs up the whole file. So I get multiple megabytes every time I back it up, even if there is only one new Email.

Finally, do you think that continuous backup is more useful than one that runs every couple of hours, or do you just get swamped with twenty intermediate versions of every homework assignment?

Thank you in advance for your help.
-Peter

http://www.acronis.ru/index.html this is good one