The new Comet Daily blog (to which I will be a contributor) is finally live, and already they are doing a better job than I ever have at explaining the value of Comet for building low-latency interactions. Greg Wilkins has an excellent post outlining the load and latency benefits of going with a Comet server vs. traditional polling.
Michael Carter (of Orbited) walks us through the details of getting the beautiful htmlfile hack to work. This is new and novel information which is useful to all implementers of Comet clients and servers, so hats off to him on his sleuthing and persistence.
Lastly, Joe Walker leads off with as post that does one of the clearest jobs of explaining why Comet is inevitable that I've seen.