I've been using the Funambol Outlook plug-in (Funambol Mobile 2.0 Messaging Powered by Open Source
) to sync my work calendar with ScheduleWorld (www.scheduleworld.com)
, then syncing ScheduleWorld with a separate folder in my Google Calendar. I keep my personal appointments in my default Google Calendar, and sync both to my 8800 with Google's new Sync app for the BB. I added the 'work' calendar to the Sync list, so I can see it on my BB, but cannot add new appointments to it (that's all done on my work Exchange server anyway).
That's a little kludgy, but I've got OTA syncing of my calendars without a BES.
I've replaced memos and tasks with IdeaMatrix and TodoMatrix, for a different OTA solution for those PIM modules. Still looking for a decent OTA contact sync solution, but those don't change often enough to really worry about.