Hi ScooterBiscuit
As Seraphim says, you would do really well to contact the CWS, I can't recommend them enough. The volunteers who work there are all really helpful and should be able to answer any questions you have about taking on the stray and what would be best for it.
The sterilisation program is about the most effective way to stop the increasing population of the stray cats. Have you ever seen the figures on how many kittens just one female can produce??? It blows you away.
There is the same system working in the part of Hong Kong where we lived and it was working there. The stray cats were fed by local volunteers and encouraged them to stay around as they in turn curbed the rat population.
Wow, that was a long story...sorry!
Where I lived there were about three cats who lived on the rocks near the water, and during that time I watched one tiny mother kitten go through three pregnancies and out of all three only two kittens survived. She was very wily and it took that long for her to be caught and sterilised. She knew I was a soft touch, and although she taught her kittens hunting etc she used to bring them to our balcony to get tidbits.
I had one favourite, and he trusted me. I would leave the door open and he used to come in to our flat every night and eat cat biscuits and sit on the couch with me, he even let me pat him and play with him, but it took 12 months and he would never stay inside evenwhen it was cold and wet outside. During the day he quite often slept on our balcony as it was cool/sheltered, but he lived outside on the rocks, and I don't know what happened to him. We very suddenly had to move flats and I tried really hard but could not get him to come with us, if ever he was in and I quietly shut the door he literally ran up the walls trying to get out when he realised he was closed in. Nothing would calm him down except letting him out again. I have pangs every time that I think I left him behind, I can still picture his beautiful black coat and piercing yellow eyes, and the little kink in his tail. I hope that he found a new friend to give him his biscuits but I hate to think of what really may have become of him.
Now we are here we have 2 beautiful cats that we adopted through the CWS. One was off the streets (a motherless kitten at 4 weeks old) and the other was 18 months old, a cat who was left here when the owner went to Shanghai. They are both sitting with me as I type this and I won't be leaving them behind no matter what.
oops that was a long story, sorry!
). There is an organization called the Cat Welfare Society that does amazing work to educate the public and help take in cats for adoption. Check them out here: 
) and live much harder lives if you leave them. I read on another thread (that I stayed out of, but wish you much love and luck on) that you might go back to Oz. Just keep the little furry fella's feelings in mind if you do decide to go. 
