There's the "popular" choices, for sure, but which login accounts you prefer to use, and prefer to have supported when you're a user of a service?:<p>Choices are (choose as many as are relevant for you):<p>a. Facebook<p>b. Google<p>c. Twitter<p>d. GitHub<p>e. StackOverflow/StackExchange<p>f. custom username/password for the site in question<p>g. [fill in your own]