The following is a compilation of free cloud applications. Many of these are useful online learning tools. If you know of a free cloud app you would like to recommend, please let me know and I will add it to the list.
Audio
Myrna (Aviary) (audio editor)
SoundCloud (share audio/music)
Blogging
Blogger
Edublogs (for teachers and students)
TypePad
WordPress
Cartooning & Animation
DoInk (draw and Animate)
GoAnimate
ToonDoo
Charts, Diagrams, and Data
Cacoo (create diagrams)
ChartGo (create charts)
Google Public Data Explorer (Create charts and visualizations form public data)
Documents
Google Drive (docs, spreadsheets, presentations, forms)
Zoho (docs, presentations, spreadsheets and more)
File Sharing
Drop.io
Dropbox (file sharing and convenient way to share a portfolio)
Graphics
Flickr (photo sharing)
Phoenix (Aviary) (Image and photo editor)
Photoshop Express (photo editing)
Picnik (photo editing)
Sumo Paint (image editor and painting tool)
Polling/Survey
Survey Monkey
Vorbeo
QR Code Generators
Kaywa
Snap.vu
YouScan.me
Quizzes
ClassMarker
ProProfs Quiz Maker
Screencasts
Screen-o-Matic
Screenr
Social Bookmarking
Delicious
Diigo (research and knowledge sharing)
Linkpad.me
Social Media and Networking
LinkedIn (professional networking)
Plaxo (networking)
Storify (create stories using social media)
Twitter (microblogging)
Yammer (corporate microblogging)
Video
TeacherTube
YouTube
Misc.
Audio
Myrna (Aviary) (audio editor)
SoundCloud (share audio/music)
Blogging
Blogger
Edublogs (for teachers and students)
TypePad
WordPress
Cartooning & Animation
DoInk (draw and Animate)
GoAnimate
ToonDoo
Charts, Diagrams, and Data
Cacoo (create diagrams)
ChartGo (create charts)
Google Public Data Explorer (Create charts and visualizations form public data)
Documents
Google Drive (docs, spreadsheets, presentations, forms)
Zoho (docs, presentations, spreadsheets and more)
File Sharing
Drop.io
Dropbox (file sharing and convenient way to share a portfolio)
Graphics
Flickr (photo sharing)
Phoenix (Aviary) (Image and photo editor)
Photoshop Express (photo editing)
Picnik (photo editing)
Sumo Paint (image editor and painting tool)
Polling/Survey
Survey Monkey
Vorbeo
QR Code Generators
Kaywa
Snap.vu
YouScan.me
Quizzes
ClassMarker
ProProfs Quiz Maker
Screencasts
Screen-o-Matic
Screenr
Social Bookmarking
Delicious
Diigo (research and knowledge sharing)
Linkpad.me
Social Media and Networking
LinkedIn (professional networking)
Plaxo (networking)
Storify (create stories using social media)
Twitter (microblogging)
Yammer (corporate microblogging)
Video
TeacherTube
YouTube
Misc.
Cometdocs (convert files, including to PDFs)
Online-ConVert (media conversion - video, audio, images...)