Reloading Portions of a Web Page Dynamically

What's the first thing you do after spending 30 gruelling hours travelling to the other side of the planet? Check your blogs of course! Seems the world has figured out what XmlHttpRequest is all about, now that Google has shown the way. (Thanks Google! - there goes the little bit of pizazz I was going to impress everyone with in the next release.)  I do wonder  about the scalability of this idea in general though - especially when used over a dial up connection (like I am using now to write up this post). It took me a while to realize what was supposed to happen because it took so long for the auto-complete feature to pop up. Caveat lector!