Sometimes...

[DanaC]

...the leap is obvious, once it's made and takes a kind of genius to think of it and make it possible.

From an article at BBC News|Tech:

Avatars ahoy

For Steve Hoffman, creator of RocketOn, the impetus for his creation came from a dream.

In his dream Mr Hoffman was browsing the web when suddenly all the people also using the site he was on rose to the surface and started chatting.

The end result of that dream is the RocketOn browser extension, which lets people create an avatar that accompanies them as they travel round the net.

If they visit a site at the same time as another RocketOn user they can stroll across the webpage and chat to that other person via the in-built instant messaging system.

Also, said Mr Hoffman, friends can meet up on one website or can gather to watch a video on another site such as YouTube

http://news.bbc.co.uk/1/hi/technology/7591982.stm

The article also talks about a web game called PMOG (passively multiplayer online game) which has people carrying out quests and setting traps for opponents and stuff across teh interwebz.

I think that's brilliant.