Can you give a lot more information about what is, or isn't, happening? We test on localhost all the time, so it definitely can work.
Questions:
* How are you authenticating? A social network or Joomla credentials? If social network, which one?
* How did you register your account?
* Are you getting errors or other messages?
Any information you can provide about your configuration or what you're trying to do will help.
Thanks,
Alex