I spent last week developing GeoProxy, an extension to set proxy for chrome. GeoProxy will list proxies based on country you choose. You can then select any proxy from that list to be used with chrome. I use this extension to access sites like hulu which are geo-locked.
How does it work?
GeoProxy uses cross-domain ajax module to read xroxy site. It then searches for ip address of top ten proxies sorted in the order of latency. Localstorage, a HTML5 feature is used to store the proxy details on client-side. So user can know which proxy he is currently using. An option to unset proxy is provided to use direct connection instead of proxy.Pretty simple.
Jquery is used to simplify coding. UI is kept as simple as possible. Check the source code here.
Download GeoProxy from here https://chrome.google.com/webstore/detail/pooljnboifbodgifngpppfklhifechoe