Zero-crossing detector?

[RussMartin]

Still with PBP and the 12F683.

I've read AN236 and AN521, and searched the forum. I'll have to admit, mains AC directly to a PIC pin, even with huge megohms in series, scares me, but I'm game to try it--assuming the '683 has the same clamping diodes on an input as the 16C5X and 16F87XA devices. (Being mistrustful, I may add external diodes . . . )

What is your preferred/recommended zero-crossing detection method--circuit and strategy and code?

I'm looking for (a) transformerless, (b) fewest components, and (c) simplest implementation.

Thanks!