There are a variety of popular services in the web conferencing arena, from WebEx to GotoMeeting to FuzeMeeting to name a few.  But now this number has been reduced by one as another popular service, Dimdim, has announced their acquisition by SalesForce.com.  That means Dimdim is no more. On March 15, 2011 all month to month Dimdim accounts will cease to exist.  Those who have paid for annual...