It definately looks like a Litoria......Kinda looks like a Litoria fallax (Easter dwarf tree frog) that we get down here but i doubt that it is.
Does it make a sound kinda like a zipper being zipped up and down really fast???? This may sound silly but it's like ZIIIIIIIIIIIIIIIIIIIIIIT ZIIIIIIIIIIIIIIIIIIIIIIT.........ZIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIT ZIIIIIIIIIIIIIIIIIIIIT