Startup Idea : Lets talk together

I've been learning English and need to improve spoken English. My spoken English is terrible. I've tried contacted people around the world many times for improving our spoken english but it usually doesn't work ( because of you have too diferent level of english, the second person isn't interested in speak to you, you don't have topic to be discussed and so on) So I've been thinking about some free website where some topics would be given and you can freely join to any and start speak to group. If you realize that the topic is not right for you or level of English is too difficult or to easy, you just leave the group and join to another whenever you have time to speak you can join to this website and start to speak. You don't need to add any person to you contact list, you don't need to thinkig about topic, you don't need to search for people who's the same interest like you, everything you'll find on this website. I made some mockup http://worldcup2010.webz.cz/LetsTalkTogether.pdf