title: Steam API Authentication
body: <p>Before I get started, let me say I know absolutely nothing about OpenID. I don't even want to do what OpenID is used for, but I imagine people will mention it, but thats not what I'm looking for.</p>
  
  <p>I have software. That software requires users to provide their Steam Username when they register. They are not signing on through Steam, just providing their username so that others know their steam username. So there is no need for OpenID.</p>
  
  <p>I know, I can simply just add a text field and have them list their Steam username and call it a day. However, doing this, people can input pretty much any steam username they want and be done. I would instead like to be able to confirm their usernames.</p>
  
  <p>Ideally, there would be an "authenticate steam account" button. People click it, and it brings up a Steam login form. People login, and then steam returns their username (and maybe some extra data, such as their avatar). What would be the best way to do this?</p>