I went to the anti-phishing working group web page and they have a nice bar chart on the number of new phishing sites by month, from November 2005 to November 2006.  The patterns seem to follow the spam trends that I wrote about in another post.  To summarize, the rate of increase in the number of phishing sites increased rapidly from June to October but flattened out in November.  This is the same behaviour that we saw in the amount of spam volume during the same time frame.  If there really is a relationship (and I'd need to run the numbers with more data, 12 data points is not enough), it would confirm the anecdotal evidence I have read in some reports that state that phishing is on the increase.