You can make Adsense more effective if you take the time to place it on your website. Try to fit it in your design so it becomes part of it. Then people will click on it faster and you'll get more money.
Also, a less ethic way of making money is a socalled Adfarme. A site full of Google Adsense colums wich all look like part of the site so people THINK they have a complete site on the screen but it's just advertising. This combined with a nice url makes a lot of dirrty money
Robin