These sites are both excellent resources, as Denis
suggests - another one is the CD 'Frog calls of ACT & se NSW' which should
be available at the ANBG bookshop. This has all Canberra species first, followed
by NSW ones.
As to the id of Benj's mystery call, hard to know
for sure but it doesn't sound like any of our local frogs, and could be from an
insect (or something else entirely!). Bleating Tree Frog is unlikely - it is not
recorded from the ACT as far as I know. Still it has an interesting call, well
worth a listen, you might hear one next time you are down the
coast.
cheers
Steve