Yes, some of them have worked ok and some of the others haven't really worked out as adsense earners. That's the way it goes, you've got to keep exploring new niches and recycling the ones that don't work. There's a couple that i've added this year that look quite promising, but three of the blogs will be dropped. I'm surprised the adsense alternatives site hasn't done better, but Google isn't really too keen on indexing it, I wonder why?
These are the ones that will get the chop I think, as it's a disproportionate amount of effort for the reward involved :
23 jan 2007 florida holiday wiki $3.16
12 may 2007 disney blog $0.96
18 mar 2007 quizweek blog $0.29
I won't be adding anything further new in the near future, but will be working to increase the traffic on all of the other sites by white hat SEO.