A guy I was speaking to recently said that he thought that Google was biased towards .com names as apposed to .co.uk's and I have been looking into it and in general the UK SEO companies with .com names have a higher Google PageRank then the UK seo companies with .co.uk names even if a site with a .co.uk has more quality backlinks the .com generally will still get a higher Google PageRank I don't know about SERP's beacuse there are many .co.uk websites with PR4's that are doing very well, however with regards to PageRank the .com names definatly seem to get sorted out more, I cannot find a single .co.uk SEO company with a PageRank higher then 6/10 where as with .com names there are a few PR7's and 8's like weboptimiser.com, bigmouthmedia.com & neutralize.com. I would be interested to hear what your thoughts are on this!
i have come across plenty of .co.uk domains when im searching on a us server, from a us ip, for a us based product so I doubt thats the case.
In google.co.uk searches, I find that .co.uk sites seem to do better in the actual SERPs than .com sites, given the same age, back links, etc
The country-specific versions of Google, Yahoo! and MSN Live now give a great deal of weight to geo-location - even if the user does not select the country-specific search filter. They all use the same two criteria for determining geo-location: (1) the presence of a Country Code Top Level Domain (CCTLD) as in '.co.uk', or (2) the physical location of the server that hosts the domain based on its IP address. No other factors are considered. Your domain registration record won't matter, and there are no magic <meta> tags. There have been some recent reports of a few .com domains not being properly recognized in Google, so I would certainly recommend getting the appropriate CCTLD if you possibly can.