Create your own avatar
voki.com

Create a free Blog
https://www.blogger.com/start

All Things Web 2.0
http://www.sacredcowdung.com/

Shared Online Calendar
calendarhub.com

Social Bookmarking
del.icio.us

Your Online Notebook
www.google.com/notebook 

Find and Watch Almost any Video
hulu.com

Visually see the page in this video search
searchme.com

Google docs, collaborate online
http://docs.google.com

Post Documents On-line for Free
http://www.lulu.com/

Multi User Whiteboard
 skrbl.com

Online Collaborative Presentations
prezentit.com

Photo Sharing
flickr.com

Social networking and microblogging
http://twitter.com/

How to show YouTube videos blocked by Security
convertyoutube.com

online conferencing for up to 100 people, in beta
dimdim.com -

video conferencing for up to 6 people
oovoo.com 

Free Internet Phone
http://skype.com/