I notice that you don't have any videos on YouTube. I think that a great way to get international exposure is to create a gridrepublic youtube account and put up some professional promotion videos. There are some people on youtube that have science and education channels with tens of thousands of subscribers. I am convinced that you could persuade some of these youtubers to feature your promotional videos that will result in thousands of users signing up for gridrepublic.
Here is a video that someone has already done: