Here’s a fun sidenote to Goldman Sachs’ investment into Facebook: The social networking company’s chief financial officer David Ebersman demonstrated Facebook yesterday to Goldman employees, according to Bloomberg.

Specifically, Ebersman walked Goldman’s private wealth-management team through how the site works and gave them pointers on how to explain Facebook to older clients. He was speaking in the firm’s San Francisco office, but his presentation was transmitted to other Goldman offices.

The news made me smile because, even though Goldman has reportedly invested $450 million in Facebook and plans to allow clients to invest $1.5 billion more, the firm’s employees normally can’t access Facebook in the office (as other articles have pointed out).

Of course, Goldman presumably had access to Facebook’s financial details, which, if you’re going to invest hundreds of millions of dollars at a $50 billion valuation, are much more important than opening a Facebook account. As Facebook moves towards the initial public offering that’s expected in 2012, it will probably have to win over many more Wall Street types who don’t use the site themselves.

Neither Facebook nor Goldman has confirmed the deal yet.

The attention paid to Goldman’s Facebook access kind of reminds me of the fuss over the fact that Aaron Sorkin didn’t join Facebook until he’d signed up to write the movie that became The Social Network. And hey, he wrote a great movie that might win him an Academy Award. It just didn’t have anything to do with how Facebook works.