Whenever I find useful tools that make life easier I will share them here. The list below is entirely subjective as it is based on my own personal opinion.
2idi : identity services provider
asterisk : open source pbx
audacity : sound editor
BB flashback : next generation screen recording
bloglines : web RSS aggregator
blogbridge : desktop RSS aggregator
box : online storage
del.icio.us : social bookmarks manager
drupal : content management platform
evernote : digital repository
filmloop : set your digital photos free
firefox : browser to rediscover the web
flock : new generation browser
freemind : mind mapping tool
gada.be : metasearch service
gabbly : cloud chat service
google earth : 3D interface with the planet
icerocket : search engine
imagination cubed : collaborative drawing tool
joomla! : content management system
jotspot : the application wiki
liveplasma : music and movies discovery engine
mediaportal : mediacenter
netvibes : personalised home page
odeo : create and share podcasts
opml : outliner for the living web
podzinger : podcast search engine
rojo : web-based rss reader
skype : VOIP
sphere : weblog discovery engine
squeet : RSS feeds via email
teamspeak : communication system
technorati : search engine
tiddlywiki : reuseable non-linear personal web notebook
trillian : multi chat client
ubuntu : linux OS for human beings
vlc media player : cross-platform media player
wikio : next generation news tracker
wikipedia : the free encyclopedia anyone can edit
wink : screencast creator
winksite : mobile site builder
wordpress : personal publishing platform
world wind : Nasa desktop application
writeboard : collaberative writing online
writely : web word processor
xen : virtualisation software
zazzle : personalised products
