Thing 17- why wiki

I can see why people get confused over the difference between wikis and blogs.  They are very similar.  For me, it seems the major difference is that with a blog others can only post comments but with a wiki others can actually contribute to the main content of the page.  I like the collaborative idea behind wikis.  Wikis also seem more appropriate for classroom projects and group work.  And I like that I can decide exactly who gets to contribute to it.  I don't think a blog would be as beneficial for displaying different projects within a class. 

I found the wikis I explored to be interesting.  I like the idea of the utopia wiki, but the way it was used did not seem any different than a blog or email:  objectives were posted for all to see and the students would chat about a variety of ideas.  I loved the depth of the discussion the students were having, but don't see how a wiki was better for the project than a number of other programs.  The wiki that used glogster was terrific!  I think that is a perfect example of how to use a wiki.  I can see myself using this idea in social studies at the start of the year when we study the Five Themes of Geography.  Each year I try a different project as a final assessment and I think this might be it for next year!  This would have also been great during the presidential election, when students were tracking candidates on the road:  they could study that region of the U.S. and then add a glogster or other project information to a wiki.  Maybe there is a way to incorporate this into our study of the census this year...

I wonder, with a wiki like the 1000 Things and Greetings from Around the World, how do others find out about it?  Or any of the other wikis that are out there for public contribution?