Theo has posted the slides of his PHP lightning talk in PDF format. The topic? Why PHP sucks.
I've never disputed the fact that PHP has problems, but for some reason, everyone who tries to explain why PHP sucks misses most of the actual reasons it does. It's astonishing.
Theo doesn't give six reasons I agree with (one or two are there for comic relief), but he starts off with three solid points. More importantly, he notes that Java sucks more, but he can't cover that in five minutes. :-)