This is truly a great anecdote. I wish I could bookmark comments on HN, because I want to dig out this one when the time comes.
You see that "X hours ago" to the right of the username? Yeah, click that...
But it's a good tip nonetheless. Once you click the "x minutes/hours/days ago" link, besides bookmarking the resulting URL in your browser or elsewhere, you also have a few more options that show up at the top of the comment page. One of them is to "favorite" the comment. You can also favorite a submission in a similar way.
Just be advised that your favorite submissions and comments lists are public.
I totally agree that this is an example of insane, hidden functionality. How could anyone know that "click timestamp" = "view details"? Makes no sense.
However, seemingly every site/app has adopted this, from Twitter to Facebook to several PM services.
Why not acknowledge that this is a problem and just add a little "Permalink" link, which some sites used to have? Or at least a permalink icon?
Surely the combined design talent of Google, Facebook, and Twitter can solve this problem better.
A hypertext system that doesn't treat links as slightly opaque, explaining them in detail wherever they appear, sounds unpleasant to me.
I guess you could probably modify most such systems to have a flashing popup on every link that said "There is more information available if you click on the text here!!!!".