Interesting that Tim Bray's weblog qualifies for AdSense whereas Ugo Cei and Jeremy Zawodny, among others, don't.  While Tim tends to write lengthier pieces, and definitely produces great technical content, he goes into personal interest territory pretty regularly as well.  I wonder if we'll start seeing ads for gardening tools show up on his site?

One interesting thing to note is that Tim's RSS feed serves exclusively extracts, never full content (well, unless the article's a single paragraph).  If you want to read the article, you have to go to the site and then you're exposed to the ads.  I doubt that Google took this into consideration, and in any case, Ugo's feed also serves extracts, so the same rule applies to his weblog.  That said, I think Tim's RSS is much more effective than the traditional implementation, where the feed is truncated with an ellipsis after some arbitrary number of words.  In fact, of all the feeds I subscribe to, only Tim and Jon Udell get extracts really right.

[later] The google ad on Simon Phipps' list of Sun Bloggers cracks me up!  I hope they don't change it, but here it is for posterity:

Way Of The Superior Man Learn the "Secret Psychology" you need to attract and date hot women www.doubleyourdating.com