29 Nov 08 Ideas on how to make money online doing what we like

I want this to be a space for people to contribute with ideas on how to make money online doing what we like. Suggestions that are welcome are:

online businesses ideas
e-books topics of interest
what kind of things people would pay for on the internet
new ways of online advertising for conventional business as a way to make money online
how someone could set up a business from home using the internet

Any comment that could help anybody interested in making money online is welcome!