A good friend of mine talks about this topic in her page recently. Check this out: http://rohiezhusain.blogspot.com/2010/10/alahai-petai-jeruk.html.
Rohie, that is my favorite too. When the season comes I used to make my own petai jeruk. What I want to relate is here in Melbourne we can get the petai jeruk too. One that I found is petai beans in tin of Ayam brand, sold in a wet market, Pascoe Vale market, I know belongs to a Vietnamese. It is named "petai in brine". Parkia speciosa is the scientific name for it (sedap didengar nama saintifiknya). We still enjoy prawn or anchovy sambal with the petai beans once in a while.
Generally, almost nothing couldn't be found here if we miss anything from the hometown, even those of the exotic one. Just name it: durian, pandan leave, kesum, curry leaves, tumeric leaves, kaya etc. Except maybe the specific kind that we like such as my favorite Kedah belacan, which was thrown away by the quarantine officers at Brisbane airport, brought by my father-in-law who came here recently. Miss the belacan so much.. :-(
Once, there was a local lady in a shop asking whether I am Malaysian and where she could find kaya (coconut cream and egg jam) in Melbourne for she wanted to taste it. I said I myself did not know. Never found it here. At that time I was just arrived and I did not know the existence of Asian grocery shops here like Laguna Asian Groceries where almost everything can be found.
See, I realize that human beings have a very special connection to their land of origin. At least represented in what we crave for when we are far away from the home land. Maybe many of the white locals here still think that they belong to their country of origin in Europe?