Xackmail is an e-mail-specific backup solution from Xackup that supports Outlook for Windows and Mail.app for OSX. When launched, Xackmail will be $2 per month for unlimited storage with simple backup and restore functionality.
Currently Xackmail is in private alpha (maybe beta, I'm not sure), but I'm very interested to know if it will allow Outlook users to archive e-mails that might otherwise wind up in PST files and/or backup and restore PST files.
neverfurget is a Mac-specific program that allow you to sync and backup all of your iCal information with your Backpack account. I'm not a Backpack user myself, but I could definitely see how this would be useful especially if you are a big ToDo user -- Google Calendar still doesn't have ToDo functionality, which bums me out as an active user.
Link -- Xackmail
Link -- neverfuget
Note: in doing some more research, Xackup actually is the parent company of Bandwagon, which maes total sense now that I know.