It would be great if there was an online resource whereby you could put in certain characteristics from a drop down box with photographic examples etc...
Looks like I finally found one. Google in Australia for Eucalink. Once there, click the identification link on the right hand side. here you will get a full page of drop down identification parameters, like location, tree type, colouring, bark type, fruit, etc etc. This one has helped me narrow down the choice of what my tree is.
There are no photos though. Once you get the name of possibles, copy/paste the term into google images or flickr.