Oddpost is most likely the best web application I’ve seen and it is a proof that DHTML can be used to create rich web applications. The second best web application I’ve seen is Halfbrain. This should come as no shock that Oddpost and Halfbrain comes from the same genius hive mind.
I got the news that Yahoo has acquired Oddpost from a co-worker and I think this is a very strategic move by Yahoo. This will make them kick Gmail’s ass when it comes to UI and usability.