Google Ad Sense
Google has just introduced Ad Sense, a type of banner advertising. They say the ads will be relevant for that website. The website gets paid when someone clicks-through on an ad. This is similar to the pay-per-click (PPC) ads you see on the right hand side of a Google search.
The Google ad appears in the right hand column. The ads seem semi-relevant. However, Ad Sense is still brand new, so I’ll give it a month or so and see how it goes.