I have been checking out Britanica Online.  It is an excellent resource.  I love some of the features such as the sample citations at the bottom which allow you to choose MLA, Chicago Style, etc.  I also found it very convenient that you can get immediate definitions by double clicking on words.

I am wondering if there is a place that tells you how recently an article has been updated.  How long does it usually take for recent news events to be added?