Oh... and in the board above, MCLR is strapped directly to Vdd. There's more to it than first meets the eye... careful positioning of components, ground-plane around the PIC and little ditties like that all come together to produce a solid bullet-proof final product.

> BTW, when you say "purely on/off", what else could it do?

By varing the firing angle you use Triacs to dim lighting for example. It's actually VERY EASY to switch Triacs badly, and so create heaps of noise and inductive nightmares (kinda apt for halloween).