One of the oldest still-existent startups that could be classified as Web 2.0 has to be Topix.net. They launched in 2002 and have been through a few changes and relaunches since then, although I think this might be their best one yet. Going live today was their new site which features a new look, interface, and features.
Focusing on local news, Topix.net is an interesting service that's been pumping citizen journalism for the past couple of years. It's amazing how local they're able to get and still maintain the quality of a regular news publisher — and I think they're new design reflects this.
One of the smart things they've done with their and certainly one of the highlights is they've enabled upto over an year of search results, which is excellent. To addon to that, they've placed an "Interactive Graph" of the search, which shows you a bar graph of when in the past year the search term has had its "bumps," and also allows you to make a selection from it, for example from December 05 to March 06, and search within that timeframe. This is quite cool.
Another thing you'll notice in their new design is that it's divided into lots of different section and that shows, just like what Technorati have done in their latest relaunch. And this is an excellent thing, certainly a trend I've seen in making usable sites. I think for the thousands of people who use the site on daily basis, it might just make their time on the site much more valuable and faster, not to mention enjoyable. And for the others, this might just be another reason to start using it.