Someone turned up at the ASNSW SPSP two or three years back with a (from memory) 36" Nasmyth design.
He had hired a furniture removal truck to get it there! That's the biggest thing I've heard about / seen in Australia - I got to look through it for about 30 seconds 'cos the queue was so big, then spent the rest of the night having much more fun comparing views through an 18" Obsession (that had fortuitously set up next to me) with those through my 4" Synta. The 4" wasn't so badly done by as you might expect - you'd be suprised what you can see through one of those with a bit of experience and some serious dark adaptation.....
Others may recall the monster scope and be able to supply more details.