Do scanners on UHFs have a use anymore?

um... you mean police et al have gone digital?

Yep, I thought in NSW they have anyway?

Is there anyone else worth listening to? Ambos, SES etc?

Most if not all Govt radio networks in Oz are now or soon to be digital. You cannot listen in on them . Most Ambulance, Fire Services, SES etc used to be on AM for which the type of scanner you are thinking off would be useless. There are many users in the FM/UHF spectrum that you could listen to however their transmissions are often infrequent and not of much interest. There is a Scanning Site over in SA that is of some interest with lists of frequencies that you can listen to. They also provide a pretty good insight to digital radio, encryption, other links etc. It might be of some use to you. Scanner Link

Ben, there's a limited amount that can be listened to in the frequency range of a uhf radio. It can be a bit of a challenge finding the frequencies to program into your radio too.

SA & NSW governments have gone to trunked networks (not sure about other states, though Vic uses a series of VHF repeaters I think).

You can listen to most government services (though in SA the police are encrypted). Although it's possible in SA to listen with a programmed uhf radio, it's a pain to do so. Much better off buying a trunking scanner.