Google Drive offers collaborative cloud based productivity tools that allow users to create and share text documents, presentations, spreadsheets, and forms.

Dropbox is a virtual storage application that allows users to access and share their files anywhere.

Padlet is a free multi-platform browser based app that provides unlimited number of simultaneous users with a live collaborative web space to embed notes, links, images, and other multimedia.

Similar to Padlet (app above), Dotstorming adds a polling feature for online collaborators to vote on notes and media posted.

Slideshare is a hosting service that allows users to upload and share PowerPoint presentations, OpenOffice presentations, Keynote presentations, PDFs, and infographics.

Join.me is a screen sharing meeting tool. The free version allows up to 10 meeting participants.

Skype allows users to video chat online and share their screens. A subscription is required for more than a one to one video conference.

Google+ Hangouts allow users to video chat online and share their screens. Up to 10 people can participate for free.

VoiceThread is a paid web-based application that allows users to place collections of media like images, videos, documents, and presentations at the center of an asynchronous conversation. A VoiceThread allows people to have conversations and to make comments using any mix of text, a microphone, a web cam, a telephone, or an uploaded audio file.