"Disable wptexturize" is the second plugin I've created for WordPress. To be honest, as far as plugins go, they don't get much simpler than this one. Aside from the header info, it consists of a grand total of three lines of code. Those three lines, though, make a world of difference to someone trying to run a site where formatting is important.
The purpose of this plugin is to stop the wptexturize filter from running on your content, the excerpt for your content (if you use it), and the comments left by your visitors. The texturizer mangles your code by converting what you actually type to what it thinks you mean. For example, the difference between "--" and "–" or straight quotes (what normal people use) and smart quotes (what Microsoft Word uses) is night and day when you're trying to run a command on a *nix system or compile a bit of code.
As was mentioned in my "To the jerk stealing my content" rant, I've recently developed a WordPress plugin that can be used to block certain countries from accessing a blog. After a few days of tweaking, I believe that it's finally ready for a public release. I give you... "Block Countries"!
I'm actually surprised at how quickly this plugin was completed. I started with ZERO idea as to how to build a plugin for WordPress but within a couple hours I had a bare-bones plugin that accomplished what I needed it to do. Of course, it then took most of the weekend to clean it up to the point where I would feel comfortable telling someone, "Why don't you try this out on your blog?".