In April 2007, Nominet conducted a survey where they discovered that in the UK people believe that a UK domain name such as .co.uk or .uk.com is more relevant to them than a .com domain. 

In an online survey of 2,324 Internet users, which was carried out for us by YouGov, we also learned that 62% believe a .uk address suggests a company is local or more relevant than a .com, and a third (32%) believe that it is important for international companies to have local domain names in order to attract local customers.

When asked about searching for a particular company on the Internet, 72% said they would visit a .uk web address above any other and only 5% of respondents would try the .com option first.

These findings are significant for anyone that is thinking about buying a domain name and I must admit that my own surfing behaviour backs this up.  The .com domain is relevant to large and international brands and those companies that sell or are marketing information to the US, but if you want people from the UK to visit your site then you are much better off getting a UK domain. 

UK domains are also more likely to rank higher for searches in google.co.uk and yahoo.co.uk for as they are recognised as being from the UK.  The other factor to consider to improve search engine ranking in the UK is ensuring that your website is hosted on servers that are based in the UK.  If you do both these things you are likely to increase your chances of attracting UK searchers.