Microblogging, with Twitter as the foremost example, is a great social phenomenon that at times may be trivial but is certainly worth understanding and leveraging from an enterprise perspective. Twitter is very useful. For example, a group of friends can quickly organize a meeting in a pub or restaurant. It is an effective tool to quickly communicate with others. It has also become a personal news-wire medium for sharing world events (good and bad). One great post for twitter  said : “Twitter has not only tipped the tuna, but by some estimation, it has already jumped the shark.”
Read complete text Newbie quide to twitter

2007 I was write about popular text on computerworld, which is called   how to get yourself on youtube for business or pleasure .
Today we constantly measure what impact do photo and video social media have on business?

First, from a business perspective, photos and videos created by employees, customers, and partners can be considered key marketing assets. A customer photo taken with a popular product, or better yet, a video testimonial on behalf of a company or product from a customer or a known expert can help sell products, especially if it is posted on your company website for other customers to see.

Second, photos and videos can also become key parts of product reference material and training aids. A photo or video of a product assembly or linkage can augment documentation, and often express more detail in a shorter time span. New hires can quickly come up to speed if they make use of video training from experts. So it’s important for business managers to consider how to enable users to create, share, and leverage this medium as a way of preserving and sharing business knowledge, developing communities, and perhaps even increasing collaboration effectiveness.

What are you thing about this subject?

In order to increase the amount of readers and comments that you get at your blog, try the following:

Be entertaining and show your personality/videos/photos
Locate relevant blogs in your niche and engage in the conversation
Promote your blog
Collaborate with your peers
Participate in other blogs
Use trackbacks (links within blogs) to connect to other blogs to keep traffic flowing
Keep your blog current

The first wiki was named for the fast “Wiki Wiki” shuttle that runs around Honolulu International Airport. “Wiki” means fast in Hawaiian. Wikis enable users to share information, form communities of interest, and build information based on collaborative data over time. The key difference from blog is that wikis enable users to co-create and collaboratively develop content that often develops into shared knowledge repositories. Users can create wikis on specialized wiki hosting services, called wiki farms, or use wiki software and host them on their own computer or on regular web hosting services. WikiMatrix enables users to find and compare features of wiki platforms so that they can choose the one that best fits their needs. A number of solutions integrate wikis with other Web 2.0 capabilities, providing hosted or on-premise services.

https://www.blogger.com/start
Key Features:

Offers free blog hosting services
Provides customizable blog design templates
Enables photo sharing
Blogging files can be downloaded to other servers for hosting

http://www.movabletype.com/
Key Features
Software that supports multiple authors

Provides customizable blog design templates
Tags and categories aid post organization
WYSIWYG (What you see is what you get) editor
Provides spell checking
Enables photo and video sharing
Licensing for personal, commercial, and educational use
Enables users to create static web pages

http://www.typepad.com/

Key Features

Fee for service hosting
Enables users to create static web pages
WYSIWYG (What you see is what you get) editor
Quick posting of photos and videos from web, email or phone

http://wordpress.org/
Key Features

Open source blog publishing application
Offers free blog hosting services
Provides multiple blog design templates
Tags and categories aid post organization
Provides spell checking and rich-text editing
Supports site traffic measurement and statistics
Integrates spam-fighting tool, Akismet