Oh ya, I forgot about this feature. I remember it having quite a viral effect - one member would sit in it for a while, but once a second and a third joined it shot up to usually 6-10+ participants. Good times.
My dream for UrbanToronto is to be host to a icon-filled clickable map of Toronto (perhaps using Google Maps). The map will be filled with various icons denoting new buildings, proposals, transit initiatives, etc. Clicking on a icon will bring up a small popup window giving the quick facts on a project and a few pictures (e.g., floors, height, architect) and a link to the related thread topic(s). Perhaps even adding filters to only see new proposals, tallest buildings, or transit improvements.