How can someone get a single character domain?

Solution 1:

It was purchased before 1993 by Weinstein & DePaolis, and subsequently sold to Paypal (or the company was bought out). In 1993 IANA reserved all remaining single letter second-level domains, and grandfathered the ones already issued. Other functional, corporate examples domains are t.co (Twitter) and q.com (Qwest).

I hate to cite Wikipedia as a source, but it has an acceptable article on Single-letter second-level domains:

On December 1, 1993, the Internet Assigned Numbers Authority (IANA) explicitly reserved the remaining single-letter and single-digit domain names. The few domains that were already assigned were grandfathered in and continued to exist.

The assigned domains in this group are the following:

i.net  INet Solutions Ltd     Future Media Architects
q.com  JG                     Qwest
q.net  Privately owned        Privately owned
x.com  Weinstein & DePaolis   PayPal
x.org  The Open Group         X.Org Foundation
z.com  HomePage.com           Nissan Motors

As of April 2009 only three domains, i.net, x.com and x.org host a web site. q.com is active but redirects to qwest.com.

Solution 2:

I'm not 100% sure but I believe it involves rubbing elbows with verisign execs, being very early on the internet (1993) and quite possibly a lot of money.