g1smd - 4:57 pm on May 16, 2010 (gmt 0)
I have "network unreachable" shown as an error in Google WebmasterTools for a number of sites in recent days.
This is the first time, ever (as far as I can remember), that I have had this error reported for any site.
There's plenty of visits and sales at a similar time. There's potentially a good explanation. The blockage was local to Google rather than local to the server.