Comment on Google Penalty Recovery by Mark.
1) Are you sure your google penalty was caused by selling links?
Why do I say this? Same thing happened to me and I do not sell links.
I have a PR5 wordpress site and it ranked high for most of my keywords for a long time. Then one day not too long ago, poof the fairy-tale was over, from the top 10 to 200 + in google rankings.
I made sure I was doing nothing bad, I was not. I cleaned up outbound links and other things and resubmitted to google. Then very soon I was back. Until this week again I was gone again, not completely but back into the 200+ postion.
2) I use wordpress and its SEOed. Do nothing bad. I think I know what I am doing. I think google might be
a) hand checking sites
b) changing things radically in its algorithm. I try to reduce duplicate content with robots plugin.
I do not know if this can help you, I am trying to figure it all out and let you know if I come up with anything.
In any event your sites are great. I am an American living in Poland and you could live very well on your website income alone.