Yeah seems alot of people are using widgetbucks at the moment and being quite successful, ive tryed it but my niche sites arnt really good for it, i make more with adsense than any other ad service.
If you want to sign up and have a look would apprecaite the refferal sign up
heres the link
http://www.widgetbucks.com/home.page?referrer=3992002