SocialSeek is a really interesting free software that lets you search the social media not just for a topic/keyword of your choice, but also the city/country it comes from. In my example screenshot, I searched for F1 in Singapore since we just had the GP here last week. Pretty decent results, not sure what's missed out though. I reckon it's a useful tool for PR folk in the region where our smaller population's social media activities often get drowned out by the rest of the world. This way one can zoom right in to the local content.