Choose a wiki tool
Wiki tool feature comparison: PBwiki
URL for free, basic teacher accounts: Click Create a wiki and select “education” as the type.
Sample wiki using this tool:
Features available: Yes/no What they call it, and how to find it Reviewer comments
No cost version for classroom use

  Limited features and file space on free version.
Safe, individual student accounts
  As of December, 2008, PBwiki version 2.0 offers the ability to register students without email addresses. Use the classroom featres to access this.
Mass enrollment/registration of students and other wiki members
sort of
  Classroom accounts generates a list of usernames and passwords FOR you
Can “see” student passwords so teacher can help the forgetful or change
see Classroom Accounts You can create a full list without emails
Multiple wikis for a single class or teacher
  Anyone can make a new wiki any time
Easy-to-find links to outside wikis and places possibly inappropriate for the classroom?
N (That's GOOD)
  Selecting education as wiki type removes this option
Advertising free
Control of access to VIEW wiki
Make it “private” on set-up  
Control of access to edit wiki
  Free accounts allow all visitors to edit if they join. You can also control edit permission by page as of version 2.0
Ability to track “vandalism” and reset to previous versions
  Improved in version 2.0. Those who edit must join first, so you can see who makes changes.
Selective permissions to certain pages within wiki
but costs money new in version 2.0 - PREMIUM feature only
Customizable “look”
Settings> skins Very limited options for free version
Page templates available
Basic set of three options in free version  
Self-created templates available
Tag any page you make with the word template, and it will show as an available template  
Includes blog features/tools
  Does include a place for logged-in users to comment on a page
Supports images
  Free version limited to 10MB of file storage. That’s not much!
Supports audio files
sort of
  Only by links to other web servers or file upload (quantities very limited)
Notifies admin (teacher) of changes via email
Check “notify my of changes” box at log-in  
RSS feed for changes available
RSS icon at bottom of page  
Supports video
sort of
Edit Can embed videos hosted elsewhere, including built in connection to YouTube
Supports file upload
Files button on each page Storage limit of 10MB on free spaces
Image resizing tool included
Easy text editor
Clickable editor  
Spell check available
Other features:
"plug-ins" (widgets)
From edit toolbar Several categories: Productivity (such as calendar), Photos, PBMagic, Video, and Chat. Some connect to outside sites with content that may be blocked or not classroom-appropriate
Other features: generate portfolio from wiki
Wiki information: portfolios Can download as a pdf or slideshow “portfolio.” Very handy for teachers seeking to grade a wiki offline or in hard copy.
Other features: “snapshot” backup
Admin> settings>backup Paid versions get full backup. Free one is text-only.
Online support
Help in upper right and in context on certain items Connects to a user forum. Forum is a bit cluttered. There is also a blog.
Human support
PBWiki employees monitor the help boards. Email support available for classroom wikis.  
Easy set-up (rate 1 to 5, 5 being easiest)
Quickstart 3 steps. Creating the wiki and defining its “key” (password)  is very quick. Steps are designed for general wiki use, not just for education, so instructions do not mention things a teacher might want to know. MANY mentions of upgrading for $.

Overall comments:

Page editor toolbar is good and familiar-looking for Word users. Quick set up.
No “see other wikis” button readily visible for students to get into trouble.
VERY easy to get started in higher ed or less restricted environment where users can self register and use the “key.”
Very flexible font formatting and choices.

Free version does not allow for different levels of user. This is a great limitation to teachers, since students can “ruin” pages a teacher creates.
Current change-over from a single key for each  wiki to email log-ins is very confusing. (The setup procedure does not explain this well.)
No page locking in free version.
Accessibility to online tools that may have objectionable “public” content, such as YouTube.
Questions and buttons to upgrade peppered throughout the site and on every wiki page. (Might be difficult for some students to “see” past these.)
Page saving appears slow to our reviewers. One page errored out.
Reminders to upgrade to premium ubiquitous and annoying.
Comments button on all pages—anyone logged in can comment.
Log in requires email address except for classroom wikis- make sure yo join a classroom!
Requires premium acct for individual passwords to a wiki.
Navigation area must be manually edited to add a new page to that area.
Navigation tab can get lost behind other tabs at the right.