To be honest I have never really had this as a problem. Whenever I check out my sites stats on Analytics I aways seem to have a mass of unexpected visitors from all accross the globe. But then I do not use multiply domains for one site, usually just a .com or maybe if it is for UK a .com with the co.uk re-directed straight to the .com

Try searching google for the ‘Coolest guy’
he should be able to help you out with your SEO problems
Ben.