Blogost – googlewebmastercentral http://googlewebmastercentral.blogspot.com/2008/09/dynamic-urls-vs-static-urls.html

URL-Rewrite
Question: Should I try to make my dynamic URLs look static?

Google Answer : It’s much safer to serve us the original dynamic URL and let us handle the problem of detecting and avoiding problematic parameters.

Question: Does that mean I should avoid rewriting dynamic URLs at all?

Answer Google: That’s our recommendation,

……….. more:

to produce static-looking URLs from a dynamic site, you could be doing harm rather than good: Hi just look at the domain on which this was posted: http://googlewebmastercentral.blogspot.com/2008/09/dynamic-urls-vs-static-urls.html So maybe the google guys will go on with drinking wine and just the SEOs should drink water in future .