incrediBILL - 3:38 pm on Sep 24, 2011 (gmt 0)
I'm surprised some people don't think the IP location makes a difference.
It didn't back in the day, but as Google ramped up their local search and improved on local results I'm pretty sure the server location became a factor weighting the results.
I had some global listings in a US-based .com, with some competition doing the same, that started to lose ground when Google improved their local results, and the local results were always truly local vs. a global .com type of listing.
I assumed the hosting location played a factor when it was a .com vs .com and not a .com vs .co.uk