dkord / mvonditter / Tomsk -> Please you possibly supply some links to shots you've taken using extension tubes? It was something I had not thought of and does seem like a versatile option - I assume if they are combined with a macro lens a ratio greater than lifesize is possible?
foxbat -> Not sure about 'left field' - more like in the parking lot! 
Good job I have a weekend in work to do further research 
roanjohn -> Looks like you're stuck with the 82 f/1.2 as unfortunately the boss won't let me have the time off to fly in and trade 
