Infinite Scroll WordPress Plugin - nice effect, when the end of the page is reached, the next page is automatically loaded and mixed in via JavaScript - so pages are built endlessly until all blog content is there. Facebook and Flickr have been doing this for some time and I somehow find it better than these "older posts" and "newer posts" links. Without JavaScript, the links should still appear, search engines will continue to index everything (although a Google Sitemap helps a lot in this regard), so it shouldn't cause any harm.