Here are the slides from a tech talk I gave at eBay last week, I called it "Don't make me wait! or how to build high-performance web apps", inspired by, you guessed it, the excellent book "Don't make me think" by Steve Krug.
There's some intimate details on YSlow's scoring algo towards the end and some stuff on progressive rendering and chunked encoding.
Thanks very much to the folks who attended the talk and thanks to eBay for organizing this brownbag. And thanks for the gifts!