I signed up for www.rworld.com which I found by accident. It is run by the Rosetta Stone company but I haven´t found any instructions on how to actually get started except by putting the language I am fluent in (English) and the language I want to communicate in (Spanish). Has anyone else tried this?

Not RWorld one but I've used a similar one very successfully

http://www.mylanguageexchange.com/ - I've had several good intercambios off this one.

It allows you to search for people by language and by city, then you can contact them and either converse bu email or arrange to meet in person. I would imagine RWorld does the same, but without registering I can't see where to look.