Publish or perish is interesting looking:
Publish or Perish is a software program that retrieves and analyzes academic citations. It uses Google Scholar to obtain the raw citations, then analyzes these and presents the following statistics: .... [Publish or perish]
Among the statistics it generates are: Total number of papers; Total number of citations; Average number of citations per paper; Average number of citations per author; Average number of papers per author; Hirsch's h-index and related indexes.
One interesting feature is that a search on a journal title returns a list of papers ranked by citation.
Now, of course, this is as good as the data in Google Scholar. I expect we will see some analysis comparing results here with comparable results from ISI.
Via Greg Mankiw.