April 2nd works for me!! And I echo Pete's reservations about the Botanical Gardens. To start the discussion around somewhere photogenic, Melbourne-y and close to Richmond: there's a couple of things in the suburb I wouldn't mind photographing before they disappear:
* The former Biscuit Factory/GTV9 on Bendigo St (-37.824565,145.011742)
* The Silos underneath the famous Nylex Clock (-37.829319,144.988836) - in fact there's a few interesting old industrial things around Cremorne, incl surviving remnants of the old Rosella Factory...
However, for an actual get-together, somewhere dense in "interestingness" WITH somewhere for coffee would be better - maybe Docklands: there's the not-yet-obliterated-by-development bits in South Wharf with the old Port of Melbourne control tower and other ephemera...

Marc!