The other week, we wrote about how to block Sidewiki users from commenting on your site. The issue was, it basically blocked all Google Toolbar users from accessing your site.
There is a new script that reportedly blocks only those who try to use Sidewiki to comment on your site, without blocking all Google Toolbar users. It named the Sidewiki Defeat and can be viewed at code.google.com/p/sidewiki-defeat.
I spotted this via a Google Webmaster Help thread. Warning, I personally did not try this, so be careful.
Forum discussion at Google Webmaster Help.

Comments:
simon
09/30/2009 07:28 pm
another option may be to use the "webmaster sidewiki" option and make the wiki so long that it takes up the entire Sidewiki space, so that any other comment always appears below the webmaster sidewiki and therefore not on the main wiki page. I'm not sure what the character count limits are though... i've asked in the webmaster help forum.
James Stein
10/03/2009 08:47 pm
It uses JS and Hash Numbers, not a very good idea... There are a great deal better solutions that are coming.
James Stein
10/06/2009 03:42 am
I have just released the only solution that truly blocks sidewiki comments. The problem with those other solutions that use javascript and hash numbers is that the comments can still be seen. What I have developed blocks comments even if the person post a bad comment and tries to share that url, the people that try to view it will still be blocked. No other solution does this. My solution also uses a database and keywords, thus giving you way more control. http://www.blocksidewiki.com is the only solution on the market that will not hurt your site and will truly block those comments. James
Christopher Regan
10/06/2009 10:53 pm
James: What happened to your URL?
James Stein
10/07/2009 12:17 am
christopher, Stupid server update changed the permissions on my public_html folder.. It is fixed now, as soon as I seen it I changed permissions back.. You can get a 50% discount on my solution + win cash and prizes by going to my forum - http://www.articlesproductions.com/index.php/topic,66.0.html James
Melinda
10/08/2009 06:35 am
Ahhhh.... does anyone see the irony in the fact this post is about blocking sidewiki yet I was able to post a sidewiki comment? I did, however, delete the sidewiki comment.
James Stein
10/10/2009 02:21 pm
Javascript solutions can not fully block comments, I have already proven this - http://www.youtube.com/watch?v=E0tPVkgMT70 My system does not use a javascript based solution. My system uses Php, MySQL, and Ajax along with cron as it uses keywords and not hash numbers. Also melinda, this blog does not have any blocker on it, I do not think... James