Since you are using http://0nestop.wordpress.com/ right now, you would have to just make a static post stating that you have moved. Just create a new "page" and state that information on it. Once you have done that you would just go to your Admin => Options => Reading and change the static page to the one you created.
If you don't mind me suggesting it, depending on whether you are leaving right away or say 'in a years time', why not just register a domain name and host here with WordPress.com and domain map that domain. That will give your visitors time to get used to the domain name versus your current wordpress.com address and when you finally move over to your own hosting, the domain will head over there and your visitors will not know the difference!
Problem would be if you want to move quickly and then the first suggestion would be better for you! When I moved over from self-hosting to wordpress.com I just brought my domain names over and it was seemless for my visitors. If I ever head back to self-hosting, it is the same. All URL's are the same when you use a domain name!
Hope that helps!