StumbleUpon is an Internet community that allows its users to discover and rate Web pages, photos, and videos. It is a personalized recommendation engine which uses peer and social-networking principles.

Web pages are presented when the user clicks the "Stumble!" button on the browser's toolbar. StumbleUpon chooses which Web page to display based on the user's ratings of previous pages, ratings by his/her friends, and by the ratings of users with similar interests. Users can rate or choose not to rate any Web page with a thumbs up or thumbs down, and clicking the Stumble button resembles "channel-surfing" the Web. There is also one-click blogging built in as well.

Toolbar versions exist for Safari, Firefox, Mozilla Application Suite and Internet Explorer, but also works with some independent Mozilla-based browsers.

eBay acquired StumbleUpon in May 2007 for $75,000,000.

Twitter is a free social networking and micro-blogging service that allows its users to send and read other users' updates (otherwise known as tweets), which are text-based posts of up to 140 characters in length.

Updates are displayed on the user's profile page and delivered to other users who have signed up to receive them. The sender can restrict delivery to those in his or her circle of friends (delivery to everyone being the default). Users can receive updates via the Twitter website, instant messaging, SMS, RSS, email or through an application such as Twitterrific or Facebook. For SMS, four gateway numbers are currently available: short codes for the United States, Canada, and India, as well as a United Kingdom-based number for international use. Several third parties offer posting and receiving updates via email.

As of July 2008, over 2,200,000 accounts were registered.

MySpace is a popular social networking website offering an interactive, user-submitted network of friends, personal profiles, blogs, groups, photos, music and videos for teenagers and adults internationally. Its headquarters are in Beverly Hills, California, USA,My Space is not their space anymore - Article on the move to Beverly Hills. Retrieved March 16, 2007. where it shares an office building with its immediate owner, Fox Interactive Media; which is owned by News Corporation, which has its headquarters in New York City. In June 2006, MySpace was the most popular social networking site in the United States.MySpace, America's Number One According to comScore, MySpace has been overtaken by main competitor Facebook in April 2008, based on monthly unique visitors.

The company employs 300 staff and does not disclose revenues or profits separately from News Corporation. The 100 millionth account was created on August 6, 2006 in the Netherlands and the site counted approximately 106 million accounts on September 8, 2006,. MySpace.com attracts 230,000 new users per day.

Facebook is a social networking website launched on February 4, 2004. The free-access website is privately owned and operated by Facebook, Inc. Users can join networks organized by city, workplace, school, and region to connect and interact with other people. People can also add friends and send them messages, and update their personal profile to notify friends about themselves. The website's name refers to the paper facebooks depicting members of a campus community that some US colleges and Category: wikt - :prep school|preparatory schools give to incoming students, faculty, and staff as a way to get to know other people on campus.

Mark Zuckerberg founded Facebook while he was a student at Harvard University."Executive Bios", Facebook. Retrieved August 16, 2008.

Website membership was initially limited to Harvard students, but was expanded to other colleges in the Ivy League. It later expanded further to include any university student, then high school students, and, finally, to anyone aged 13 and over. The website currently has more than 100 million active users worldwide."The Facebook Blog", Facebook (login required). Retrieved August 26, 2008

Facebook has met with some controversy over the past few years. It has been blocked intermittently in several countries including Syria"Red lines that cannot be crossed", The Economist, July 24, 2008. Retrieved August 17, 2008.

and Iran.Shahi, Afshin. "IRAN'S DIGITAL WAR", Daily News Egypt, July 27, 2008. Retrieved August 16, 2008.

It has also been banned at many places of work to increase productivity.Benzie, Robert."Facebook banned for Ontario staffers", TheStar.com, May 3, 2007. Retrieved August 16, 2008.

Privacy has also been an issue, and it has been compromised several times. It is also facing several lawsuits from a number of Zuckerberg's former classmates, who claim that Facebook had stolen their source code and other intellectual property.

Friendster is an Internet social network service. The Friendster site was founded in Mountain View, California, United States by Jonathan Abrams in March 2002Metroactive Features | Friendster and is privately owned. Friendster is based on the Circle of Friends and Web of Friends techniques for networking individuals in virtual communities and demonstrates the small world phenomenon. It currently has more than 70 million members worldwideAbout Friendster and is mostly used in Asia Social Networking Goes Global by comScoreSocial Networks Size & Growth - Asia by Pipl. Based on Alexa.com, Friendster ranked 2nd most visited website in the Philippines while Yahoo! is the most visited website in the Philippines, and third party friendster-layouts.com is 16th. Philippines - Alexa Top 100 It is estimated that nearly 90 percent of internet users in the Philippines have Friendster accounts. Inquirer.net: RP has highest percentage of social network users -- study David Jones, vice president for global marketing of Friendster, said that "the biggest percentage of users is from the Philippines, clocking in with 39 percent of the sites traffic''." Inquirer.net: Filipinos are prolific, go and Multiply

Multiplication of whole numbers is the mathematical operation of adding together multiple copies of the same number. For example, four multiplied by three is twelve, since three sets of four make twelve:

:4 + 4 + 4 = 12.\!\,

Multiplication can also be viewed as counting objects arranged in a rectangle, or finding the area of rectangle whose sides have given lengths.

Multiplication is one of four main operations in elementary arithmetic, and most people learn basic multiplication algorithms in elementary school. The inverse of multiplication is division.

Multiplication is generalized to many kinds of numbers and to more abstract constructs such as matrices.

Xanga () is a website that hosts weblogs, photoblogs, and social networking profiles. It is operated by Xanga.com, Inc., based in New York City.

MyBlogLog is a social network for the blogger community that is based in part on interactions facilitated by a popular web widget that many members install on their blog. Bloggers sign up for free accounts on MyBlogLog and can initiate a blog community for one or more blogs they author. Other registered members can subscribe to these communities, effectively bookmarking them for future reading and sharing them with their own contacts. Bloggers can then display widgets on their sites which show MyBlogLog online community members who have recently visited their page. These widgets also contain links to visiting members' community pages, and are one way in which users connect with one another. All members can see certain basic information about how many people visit their blog, what links they clicked and where they come from. Members may also view more extensive information about traffic on their site for a monthly fee.

MyBlogLog communities revolve around an individual blog registered by that blog's author. These communities have anywhere from a few to thousands of members. Communities that are particularly popular, have the most members or that are brand new are featured on the MyBlogLog Communities page. Members can also find communities via searches for key words or tags.

MyBlogLog members are displayed and searchable in a largely similar fashion to MyBlogLog communities. Featured, popular and new members are displayed on the MyBlogLog members page. Users can also search for members and get a sense of who they are by seeing which communities they are a member of and what tags have been associated to their profile by the MyBlogLog community.

MyBlogLog was acquired in January, 2007 by Yahoo for slightly more than 10 million dollars and with over 45,000 blogs subscribed at the time.. Currently, MyBlogLog averages approximately 22 million visits to pages with MyBlogLog widgets each day, and the site has over 275,000 registered members. MyBlogLog has an Compete.com rank of under 2,500 and Google PageRank of 7 out of 10.