Wuala

All files encrypted and stored redundantly. No one unauthorized - not even Wuala as the provider - can access the files. Password never transmitted.
Sync files across multiple computers, share with only who you choose.
Data is stored in multiple places, old version and deleted file restoration.
One click auto sync.
Sharing via folders for registered users and link sharing with no registration required.
Business version allows business groups to access the files.