I'm wicked busy with law school these days and haven't been paying as much attention to interviews as I'd like. Don't worry.
For now, watch this clip from the BBC's incredibly incredible Life of Birds series. In it, Master Attenborough calls a woodpecker down to him by mimicking his tree-knocks.
It works for North American wookpeckers, too. One time in upstate NY I called a Red-Bellied Woodpecker (I think, maybe a Sapsucker) into my by copying it's double-knock. Great times.