I have a site listing american restaurants but I keep getting ads from things like uk restaurants guides. Apart from individually filtering out the urls is tehre any way to specify that you want ads only from say american sites, or .coms rather than .co.uk's?
I'm taking it that you are visiting your site from the UK. Adsense Ads are shown according to the location of the visitor. Visitors from the US will see ads for the US market without any problem. Actually it makes quite a lot of sense. Let's say you are looking for a bed. You are far more likely to order it from your own country, than importing it from overseas.... So in the end I would suggest that you don't worry about it. Your site is most likely targeted at the US market, and seeing as most of your visitors will be coming from the US then the appropriate ads will be shown.