Note: I originally wrote this a while ago and never quite got around to finishing it, but I'll present it anyway. If you have comments, please let me know.
The <a> (anchor) element in HTML is the most
important tag in the entire HTML definition; without this tag, there
would be no hypertext (the "HT" in HTML). However, I believe that
there are some issues that should be looked at when using
<a>.
As displayed by default, links are annoying, especially when a sentence contains a lot of them. In the sentence above, your attention was almost certainly diverted by the blue, underlined links. Having a large concentration of links with small link text makes it harder for readers to wade through your pages.