Web site backup in PHP?

Does anybody know a clean PHP-based solution that can backup remote web sites using FTP?

Must haves:

• Recursive FTP backups
• Possible to run through a cron job
• Easy to configure (easy adding of multiple sites)
• Local storage of backup files is sufficient

Would be nice:

• Backed up sites are stored as zip files
• A nice interface to manage things
• Provides notification when backup has succeeded or failed
• Does incremental backups
• Does MySQL Database backups

I need this to be PHP based because it's going to be used on shared hosting packages that do not allow usage of the standard GNU/Linux tools.