When is a wikki worth the trouble?

You are right.  There are many ways to disseminate information.  What I like about a wiki is that students can do group work.  For me, this makes it slightly better than a blog where students can post and comment.  (I like a blog for writing journals, but overall I like a wiki better.)  Also, I post grammar review exercises and sample tests, which students can work on on the wiki.  This allows me to make comments and corrections.  They can help each other, too.  (I teach ESL to adults.)

I use the wiki like a giant crazy website.  I have links for geography news and tidbits, videos, all the class powerpoint files, and for their exams I have a take home portion that uses Google Earth.  I post the links for the one night that they are doing the exam.  They have to use Google Earth to evaluate the places in the links, and within the links I have put the actual questions.  As it turns out, I don't have to print out a huge amount of the exam, because the students type up their answers and turn them in.  I don't worry about copying from one semester to the next, because all I have to do is change the link location.  If they are using last semesters locations, they're busted.  I have students tell me that they've never had so much fun taking an exam, and they overall are learning more about the world in which they live.

Just because we can use a wikki for routine postings like home work and sharing student work doesn't mean that the wikki is the best tool for the job. 
What are the characteristics of wikki posting that make wikki the best if not the only way to get the desired results.

-cherry

Although I disagree with the premise implied in the title to this thread (what's so troublesome about wikis?), I totally agree with your advice about using the best tool for the job. From a library research perspective, this is a strategy I stress continually with students who automatically use Google or Wikipedia as their "go-to" research tool, when a subscription database or, heaven forbid, a book may provide far more comprehensive and authoritative coverage.

I find it helpful to use wikis to create quick web sites for communicating information. No special skills are required to establish an online presence; if you can type, you can have a simple website via a wiki in minutes. My school district strongly encourages teachers to have web sites for communicating with students and parents. For years, professional development trainers have struggled to teach teachers vrious web-authoring tools such as Dreamweaver, Front Page, and Expression Web, but the learning curve for these is just too steep for the simple types of web sites that teachers need. I can get a teacher set up with a wiki and working independently in a matter of minutes. Wikis are easy to learn and just as easy to maintain.

Wikis are also a great option when students are working collaboratively on projects and need a repository for the information they are finding or producing. Among the advantages of a wiki is its 24-7 availability from home or school. So if students are working on their own at night or on the weekends, they can still post to the wiki. That's something they can't do at the moment with files on our school network.