SMS Text Message is a plugin for WordPress to allow blog owners update their readers via SMS. Although I would not call it an Essential Plugin , the free WordPress Plugin to send SMS adds a nice trendy feature to the blogs.
With so many people depending on their PDAs & phones to socialize on the internet & even to browse, this plugin could help bloggers send out updates or important messages to readers.
The SMS Wordpress plugin is created by Michael Torbert.

Ever since the battles between the various top social media networks have given media ample food to talk & write about, the webmasters’ groups have joined the battle with their own Social Media Optimization buzz.
Now we have two highly popular jargons - Search Engine Optimization (or SEO) & Social Media Optimization (or SMO).
While Search Engine Optimization relates to the various theories, principles & practices that enable a web site or blog to be indexed favorably, Social Media Optimization focuses on how to leverage the various social media networks like MySpace, …