I decided to write a post to describe the features of the plugins that I wrote, and upgrades that I made to existing plugins to others can benefit from their use as well. You can see the actual source code, or else read my feeble descriptions.
User Comments by Jon Daley:
Description: This plugin lets me have this page where you can show all comments by a particular user.
There is probably a better place for this function to live, but I needed it, so put it here. On my page, I use a form to allow people to pick which user's comments they want to see. You could use this to get any variables that are on the URL via the standard ?var1=val1&var2=val2
This function will return an array of usernames who have commented on the posts. The input is either 'SITE' or 'BLOG', where 'BLOG' is the default. I actually haven't tried the 'SITE' option, since I only have one plog with comments.
getComments(username, maxcomments=all, based=BLOG)
Given a username, this function will return an array of comments posted by that user. If you only want a certain number of posts returned, set maxcomments to that number. See above function for description of the based parameter.
This function also seems like it should exist somewhere else, but I didn't see it anywhere. It returns an Article object given an id number.

Authentication by Daniel Kehoe:
Description: This plugin lets me have more links when I am logged in, rather than just a visitor. As far as I remember, I didn't change this plugin.
Given a userid, this function returns true if that poster is the current user.
Returns the name of a poster given his id.
Returns the name of the current user

Blog Statistics by Minstrel Chiu:
Description: This is how I get the statistics as to how many unique visitors on the about page.
I fixed up some typos, as well as made the database accesses more efficient. Additionally, I commented the table creation code that is only needed the first time. If you want to use my copy of the plugin, you will need to uncomment it, at least for the first use.
lots of functions
There are really too many functions to comment on here, they are all pretty self explanatory by looking at the configuration code for the plugin.

Category Browser by Jon Daley:
Description: My first plugin. This is how I get the previous/next/first/newest in category links for each post.
getPrevArticle(articleId, blogId)
Given a blog id and an article id, this function will return the previous article in the same category.
getNextArticle(articleId, blogId)
I'll bet you can guess how this one works...
getFirstArticle(categoryId, blogId)
Given a category id and blog id, return the first (earliest) post in that category.
getLastArticle(articleId, blogId)
I'll bet you can guess how this one works...

Google Highlighter by The pLog Team:
Description: I fixed this one up from the original, so it works with google custom searches in addition to a regular search. When a user clicks on a link from google, this plugin will highlight their search times, so the words are easier to see. See the plugin for the usage.

Recent Comments by Mark Wu:
Description: This plugin makes the "Recent Comments" section of the sidebar work.
getRecentComments(maxComments=20, based='BLOG')
Get an array of the most recently posted comments.
This plugin, like the UserComments plugin, also needed a function to get an Article object given an article id. Sounds like this functionality should be added to templateUtils or something.

Top Read Posts by Mark Wu:
Description: This guy makes the "Most Read Posts" section of the sidebar work, where you can list most popular posts.
getTopReadPosts(maxPosts=3, based='BLOG')
Return the maxPost most popular posts. Get them from the 'BLOG' or the 'SITE'.
Posted by Jon Daley on December 15, 2004, 6:46 pm | Read 6784 times
Category Programming: [first] [previous] [next] [newest] Internet: [first] [previous] [next] [newest]
Note, these plugins now only work with pLog 1.0.
You can download the 0.3.2 versions if you want.
Posted by jondaley on December 21, 2004, 2:46 pm

I was just looking at the code today and remembered that I never tested any of these plugins in "site" mode.
I don't expect any problems, but I haven't gotten around to verifying that it is fine.
Posted by jondaley on January 10, 2005, 9:05 am

Hi jondaley: You done a really great job about plugins... Amazing. :D About the "site" function, I think there is no problem for plugin itslef, but maybe some problem when url request generate by pLog. Because current post/comment url request generate is based on "current" blog. So, that say, if you get a post id=10 and the post is belong to blog id=2 from these plugins. You will get http://your-blog/index.php?blogId=1&postId=10, it is wrong, need some work around here. Regards, Mark
Posted by Mark Wu on January 11, 2005, 7:28 pm

Another note, some of these plugins don't work in 1.0 if you have caching turned on.
Because of that, I only use RecentComments and CategoryBrowser. I will have to work on porting the rest later.
Posted by jondaley on April 4, 2005, 1:49 pm

For some reason, spammers like this post to post spam on -- so far, I think all of them have been caught by the bayesian filter, but I am going to shut down comments for this post. Feel free to post a comment somewhere else if you have a question.

A bunch of this post is out-of-date anyway, since I am now running 1.1 on this installation.
Posted by jondaley on April 17, 2006, 8:07 pm