However, like many flaws with HN's underdeveloped software, you can't actually do that on HN because the parser includes the trailing > in the URL. So your best bet here is with whitespace.
I'd argue that the world has moved on since 1998. We live in a world full of URL parsers of various abilities, and doggedly enclosing URLs in angle brackets because of a memo written so long ago it also references gopher seems stubborn to no obvious gain. Given the state of the modern internet, I definitely wouldn't consider angle brackets to be the best way to delimit URLs.
