Scribd enables you to upload documents of varied formats—including PDFs, PowerPoints, Word docs, and EPUB—and make those documents searchable (across the web and within the documents themselves), social, and embeddable in websites and blogs.
ShareThis is an embeddable button or widget for blogs and websites to allow readers to easily share content via email, instant messenger, bookmarking services, and social networks.
Skype is a software application that allows users to make voice calls over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system. Skype has also become popular for their additional features which include instant messaging, file transfer and video conferencing.
SlideShare is a popular service that allows users the ability to upload and share publicly or privately PowerPoint presentations, Word documents and Adobe PDF Portfolios.
Sonico is a social networking platform that targets users in Latin America and stresses its privacy controls. It is available in English, Spanish, and Portuguese.
Twitter is a free social networking and microblogging service that enables its users to send and read messages known as tweets. Tweets are text-based posts of up to 140 characters displayed on the author's profile page and delivered to the author's subscribers who are known as followers. Senders can restrict delivery to those in their circle of friends or, by default, allow open access. Users can send and receive tweets via the Twitter website, Short Message Service (SMS) or external applications.
Ushahidi is an open source platform that was initially designed to crowdsource crisis information via SMS and online messages, which appear on a map interface. It is used frequently by election monitoring groups and is also used to visualize basic information on a map interface.
Ustream allows anyone with a webcam and internet connection to broadcast video live. Users watching the streaming video can optionally chat on an interface to participate. The Ustream Producer desktop application gives video creators more control over their broadcast.
Wikia (formerly Wikicities) is a free web hosting service for wikis. It is free of charge for readers and editors, and relies on advertising, and publishes all user-provided text under copyleft licenses. Wikia is a for-profit Delaware company founded in late 2004 by Jimmy Wales and Angela Beesley of the Wikimedia Foundation.
