See the question [Should the beta badges stop being awarded to users?][1] about awarding of the Beta Badge.

You can also check out the [FAQ on Area 51][2] to learn about the Beta Phase:

> Perhaps the most important phase. This is the actual, live site set up on a "probationary" basis to see if people will use it. It is very important to participate early. The earliest questions will set the tone and topic of the site for a long time. This is also the time to spread the word via Twitter, blogs, and email far and wide. If the site does not get used, it will be deleted.

When a Stack Exchange site goes from Commitment Phase to Beta Phase, for the first week, only those users who Committed to the proposed site will have access; this is so they can [prime][3] the system with content before it goes public.

Back in the day, Stack Overflow, Server Fault (and all those other links at the bottom of this page) went through their own private Betas; all users who participated in them (back in the day) got the badge.

So that boat has kind of sailed; you can't get a Beta badge on SO, Meta.SO, SF or SU.

But you can commit to proposals on Area 51 and then get the badge on _those_ sites.


  [1]: http://meta.stackexchange.com/questions/13/should-the-beta-badges-stop-being-awarded-to-users/19#19
  [2]: http://area51.stackexchange.com/faq
  [3]: http://en.wikipedia.org/wiki/Pump#Priming_a_pump