I just had a little scare with Outlook. After installing VSTO 2010 beta 2 64bit on my system my Calendar folder was suddenly corrupt. Luckily there is an excellent (free) way of repairing a broken .pst file. It’s just a little hidden. Read this KB article to find out how to do it.
Tip to Microsoft: Why not register this file as an “Repair” option to a .pst file, allowing me to right-click and fix my broken .pst file?