g1smd - 12:45 am on Oct 11, 2007 (gmt 0)

>> Talking about observation even Matt Cutts' blog takes a hit these days. <<

Matt has explained, several times, that he does not have a 301 redirect installed for domain canonicalisation, and has several Duplicate paths that are open to spidering.

He uses his own site to see how Google copes if he changes to and from www and non-www in Webmaster tools, and other changes, from time to time.

.

>> Google has steadily shown between 19 and 19.5 million results for the prime keyword of one of my sites. ... ... Today the same term shows 48 million results, 30 million more than ever before <<

Check the IP address of where those results are served from. It is likely you are seeing a different IP address each time.

I referred to this only yesterday, in this thread, with an example, too.