How to recover 'Reminders' wiped out by Mountain Lion?
You should be able to find them if you're using Time Machine, but it might take a little digging. I'm not quite brave enough to use Mountain Lion so I can't say with certainty, but I believe the reminders are actually stored as calendar items, so you should be able to find them in the "Calendars" folder in the Library. You might want to use the Finder interface to look through the backups instead of Time Machine. The iCloud calendars should be stored as random number "caldav" folders. You'll have to look inside each folder until you find the reminders you're looking for. You can then drag the files into the Reminders app which will allow you to import into a list. Hope that helps.