I've created the free application/AddIn OutlookAll2One.
Why? Simply, my nokia phone only can synchronize with one outlook calendar, and I have multiple calendars (Personal, Work, Family, ...).
Really its a workarround, the application "copy" all calendars you select to a single calendar. And then you can sincronize it with your phone/pda/etc.
To make it 2way synchronization, I put a prefix in the subject of every item, then if you create an item in your phone, and the subject starts with for example "P:", it will be copied to "Personal" calendar (because it is configured with "P" prefix).
The application have a reset button to remove all "duplicated/copied" items.
It's tested in Windows7 64bits and Outlook 2010 32bits.
Download:
http://dl.dropbox.com/u/22894763/RTKSoft-OutlookUtils.zip
Instructions:
