I created 6 or 7 Squidoo lenses last winter as a way to build inbound links to my websites and kind of forgot about them. A few days ago I logged into Squidoo and found that I had earned $1.65. Not alot of money I know but my theory is that if I can make $1.65 then I can double it and make $3.30. If I can make $3.30 I can double that and make $6.60 and so on. You get the idea.
Squidoo shares its Adsense earnings with those who create lenses. I found a formula once. The more highly your Squidoo lens is rated the higher your percentage of earnings. Here is an examples of my squidoo lenses:
http://www.squidoo.com/CurlyShoelaces