ThemePerPost is ideal for people who want to style their about page, create a unique landing page, show theme previews for design showcases, split one WordPress install into multiple sub-sites. It’s for anyone who wants to have posts and pages with different styles. All you have to do to change theme for one or more posts or pages is upload the theme you want to use to the usual WP theme directory add a Custom Field to the page/post you want to style.
Contact Form plugin from 123ContactForm.com. It requires a free account on 123ContactForm.
Inserts the lovely little table of contents you see on many of the pages of my website. It uses jQuery to inspect the content of your post or page and generate table of contents links based on the header tags. It’s easy, SEO friendly, and highly customizable.
Disable the search capabilities of WordPress.
Makes it easy for you to add Facebook Connect functionality to a site. Modular: activate only the pieces you need.
Helps tell search engine bots the preferred version of a post page by specifying the canonical properly within your head tag.
This all-in-one SEO plugin can handle titles, meta, noindex, canonical tags, 404 monitoring, robots.txt, and more. Version 1.4 adds the Internal Relevance Researcher module.
Twitter Tools is a plugin that creates a complete integration between your WordPress blog and your Twitter account.
This plugin allows you to easily integrate Google Webmaster Tool, Yahoo SiteExplorer and Bing Webmaster Central with your blog.