I would much rather see a more mnemonic approach for links, where you would write either _click here_ [http://wherever.com] or _click here_ (http://wherever.com). The underscores look like an underline, which is the traditional appearance of link text in HTML. It's easy to remember. Whether the URL is in square brackets or parentheses (maybe either one would be acceptable as long as they are a matched pair) doesn't matter, but underlining the anchor text is the way to go, IMO.
Why not _click here_ [http://whatever.com] as a more natural way to do it? The underscores imply underlined text, which has traditionally meant inline link, followed by a single, square-bracketed chunk that is obviously the URL?
(I'm not saying here that the resulting link anchor text has to be underlined, just that this pseudo-underlining serves as a mnemonic for writers and readers of the raw markup.)