These won't be worked on until Mw3 has come out, but as of now, they don't exist. So don't get fooled if someone offer's you one on here or anywhere else until there is a website and proof of there actually being one.
There are 15th lobbies offline, but your banned within 1 minute of putting black ops in your Xbox 360 harddrive. So escentially there are no 15th Black Ops lobbies. Sorry