Uhm, yes you can. When I add an iCloud account under mail, contacts & calendars it has its own Reminders and Notes switches, separate from the ones in the main iCloud account. Maybe this is new in iOS6, but right now this is definitely possible as far as I can tell. This solution seems ideal for what people want in this thread: create a main iCloud account for all to share across devices and one or more Macs. This is just used for photo stream (and possibly Find My iPhone / iPad etc and other services you want to share). Then, add an individual iCloud account for each user under Mail, Contacts, Calendars (beware: it cannot be added in the main iCloud settings section, only under Mail, Contacts, Calendars). You can then use this individual iCloud account to back up mail, contacts, calendars, reminders, safari bookmarks, notes and find my iDevice. Great solution as far as I can tell, as long as you don't care about syncing Documents and Data and Passbook through iCloud.