Good stuff on DirectCast
Paul Vick posts up some great stuff for anyone who has ever been confused about DirectCast and when to use it compared to CType.
Personally, I tend to go the opposite direction that Paul recommends and use DirectCast all the time, unless I know that the type might possibly be a different type and actually need converted, that way I can never blame it on casting for any performance issues that may arise, although very unlikely. As apposed to Paul's suggestion of using CType more often. There really shouldn't be much of a different, just a "coding preference".