Our No wpautop Pages plugin for WordPress (used on this site) is now available through the WordPress Codex.
What this does is really pretty simple.
WordPress uses a built-in function called wpautop, that adds <p> tags and new lines to content that you put into WordPress. On the whole this works great. When you edit a blog post it lets you write it like an email rather than a block of HTML.
But what happens if you want to write your own HTML? Well, you can use the HTML editor obviously, but the content is still run through the wpautop filter before being sent to the browser, which can cause problems.
So we wrote a quick little function that disables wpautop for Pages, but leaves it intact for posts. Best of both worlds for us.
For more information on the plugin, check out the No wpautop Pages plugin page.