Stuart Harrison, Simon Knott, and Christine Phillips brought Melbourne a weekly dose of architecture on the radio from 2004 to 2014, with a few more recent episodes.
This much-missed Melbourne-focused show was available online, but now (January 2019) only fragments are. RRR subscribers can search “the architects” at the RRR website for a couple of later episodes.
Some early episodes from 2004 to 2006 can be found at Stuart Harrison’s website.
The largest trove I’ve been able to find is at Libsyn, using this search. Scroll to the bottom to force more to load (be patient). I’ve no idea how far back it goes. (April 2022: this seems dead too now :( ).