Pfui - 3:37 pm on Jul 9, 2011 (gmt 0)
I've got a bunch of sites 'in' GWT and for as long as I can remember, my hitting GWT's "Home" means GWT hits my 'homes' for their favicons to display on that page. Hits are always by IP address, always with a blank UA, and typically hail from the standard ranges.
For example, here's this morning's Home run lineup (partial listing):
I block all blank-UA requests and I don't need my GWT Home prettified with my favicons. But where GWT's hits do come in handy is they immediately confirm G IPs and whether or not my blocks are still working.