The month of May produced $37.60 worth of adsense income for us from our blog, but only $4.65 of that was in the last 7 days. That compares to $33 or so in the month of April.
When I check in at a blog that has adsense, I make an effort to visit one or two of the advertisers. I know that they are all prescreened so that there is no chance of getting a virus or anything. I try and pick an advertisement that looks like it might be something I'm interested in...you never know, I might end up buying from that advertiser!