Save the Sideshow!
Right! I've been in contact with GNW TV, the brilliant production company behind The Sideshow. They've given me some details on how we can save The Sideshow (and I've dug up some details of my own).

The ABC switchboard is at (02) 8333 1500. From there, you can ask to be transferred to Complaints, or Consumer Affairs. You can also ask to speak to Programming (under Television). If you feel like going up high, the Executive Producer on The Sideshow for the ABC's side is Megan Harding, and the head of ABC TV is Kim Dalton.

Another tip - watch the show tomorrow night and note down any interesting names or positions for the ABC that you can contact.

For a more textual approach, the ABC's Have Your Say message board is located here, although I can warn from personal experience that it takes ages for anything to happen on there, and sometimes topics don't show up at all.

For a main approach, you can use the ABC Contact Us form. Make sure to note that this is a Complaint, that you require a reply, and that the program in question is The Sideshow.

And finally, I've made a petition here. Spread this link to everyone you can think of! Message boards, other communities (I'm tackling tv_australia, abc_comedy and aussielj, but please spread this to any others you can think of!), random strangers in the street... the more names we have, the more successful we'll be.

Good luck!