Their fruits (and those of their close relly Schinus terebinthifolius) are a widely used spice - dried or brined as 'pink peppercorns'. These trees are native to South America, but people have carried them around the world, and in parts of Australia and South Africa they're invasive.
Note that in New Zealand Schinus terebinthifolius is on the National Pest Plant Accord, however, Schinus molle (which Colin seems to have) is not. One distinguishing feature of Schinus molle is its longer, narrower leaf.
More good ID photos on google images.
Poach fruit in them
Crush them into meringues
Sprinkle them over panna cotta or infuse them into icecream.
Colin plans to harvest his peppercorns, then dry some and brine the rest. I can't wait to hear how it goes. (And thanks to Colin for these photos.)
If you have pink peppercorn trees growing near you, or have harvested their fruits yourself, I'd love to hear about it. (Also - I'm interested to know, is there any evidence that Schinus molle could become a pest here like Schinus terebinthifolius?)
P.S. Blogger is driving me nuts right now with its crazy ever-lengthening paragraph breaks! Am I the only person this is happening to? Is there something I'm meant to do that I'm not? Help welcome! :o)