There are some things that become so ubiquitous and familiar to us - so seemingly obvious - that we forget that they actually had to be invented. Here's a case in point - the weblog post's permalink. I mean - let's think about it. The problem was that a weblog's front page is by far its most visited page. This is the page where everyone actually sees your content (or at least it was until the creation of RSS feeds). But it's not possible for someone to effectively bookmark or link to that particular entry on that page, because shortly it will scroll off the bottom. Added to that, bookmarks operate at the level of pages, not posts. So how do you handle that? How can you make it possible for people to link to something with a higher level of granularity than just the page? Moreover, how can you get them to link to something that's not actually on the page you're looking at?

On Permalinks and Paradigms... (plasticbag.org)