Me and a friend had one goblin invasion in multiplayer a day or two, and completely smashed them in demonite gear. I ended up picking up two pairs of rocket boots from that, and gave one of them to him since he didn't find any. They're really nice, aside from using up your mana, but I've maxed out that mana due to building a dirt skyroad for collecting stars and red mushrooms.
Minor flaw with the skyroad: A meteor struck it, and left only a tiny amount of meteorite ore. This is on a large map, though, so there's a ton of space for meteors to land in.
Also got a sunfury from bone serpents last night.
I've got them combined with a red balloon (from a floating island), a band of regeneration, an obsidian skull, and I swap between flippers, hermes boots, and cloud in a bottle. Interestingly, if you have both cloud in a bottle and rocket boots equipped, you have to triple jump to activate the rocket boots.
We've got an uninterrupted two-tile-wide shaft leading from the surface down to the underworld which we can just jump down and freefall until we reach the underworld (or just before), arresting our fall with grappling hooks, cloud in a bottle, or rocket boots.
I have a smaller blue mushroom farm than the ones you folks have posted screenshots of, but it has a thick clay layer, it's underwater (The mushrooms regrow
fast), floating in the air (detached from any other surfaces), with a large amount of open space above it, so that I can see if any of the large mushrooms will grow naturally under these conditions. (I'm wondering if I'll have to avoid harvesting the small ones for a while, if that would affect it, hmm. Of course the mushroom trees may simply not grow at all.)
And I built a water and magma reservoir and obsidian creation base out of glass yesterday, using this concept:
http://www.youtube.com/watch?v=CTYeS2vB1ug