Google Adsense

When I signed upto blogger I got an email about google adsense. Reading through it and doing some research, there are people out there making a decent amount of cash out of it.
The basic premise is that you let google put adverts that should be relevant to your blog.
If people click the links and actually go to a advertised site then you get a few cents.
I've been impressed with the relevance of them so far, one for bone fractures, one for NZ, and one for flight.
Have a look at them, if enough people click through them regularly enough there might be enough money for a drink or two when we get back.