I wanted to mention another bit of insight I've gotten into the workings of that italki site.

The most useful function that is free might be "Language Partners". It probably doesn't require an explanation. The only thing is, people seem to be focused on Skype conversations. For me that's simply not an option. Even when you just get me into live chat, I'm not going to be able to sleep all night because of excitement and anxiety. Talking with foreigners - I'm probably going to get a heart attack.