In the past months,several annotation tools appeared, almost all of them based on plug-in technology. The biggest players are Google and Yahoo, promising smaller start-up services are Diigo, Wikalong and Stickis.

"Throughout the last year I found the idea of social annotations quite appealing and useful...."

MyStickies.com allows you to add post-it notes to any web page. To do so, you need to sign-up for an account and install the Firefox browser extension.

Third Voice was WebAnnotation software: a way to "post sticky notes" with your comments on any site on the Web. Others in your group, or everyone using the Third Voice product could see them.

LLuna2 lets you meet other people on web pages... with animated avatars, video, bubble chat, private chat, and personal profiles through the Jabber protocol.

Chat live with other people who are looking at the same website as you!