wish I knew how to clean the fungus..

@perder. I don't have any Nikon lenses for my GH2, but I do have many Canon FL lenses. As I buy them at very low cost on eBay, I take them to a local company that services them--takes them apart, cleans them, calibrates them, lubricates them, all for about $100. Surely there are firms that do the same for Nikon lenses.

@sdbest: With fungus, it's different. Fungus actually etches the glass, it doesn't just grow on the surface. Once your lens gets fungus, it's basically toast. Fungi reproduce through spores, which get in everywhere inside the lens. You'd have to completely disassemble the lens and decontaminate each piece. If your lens has fungus in the very early stages, it's possible to clean the lens element, as long as the fungus hasn't started etching the glass with its acids; with an older lens that has been in storage for an indefinite period and has fungus, I wouldn't bother buying it. It's much easier just to find a lens without fungus. Sunlight and ultraviolet light will kill fungus, so regular lens use helps keep your lens fungus-free. In humid climates, a drying cabinet will work. I have heard of cases where people locked their lenses up in a safe, but forgot to add dessicant inside the safe; the resulting warm temperature, humid air, and dark environment resulted in fungus growth within days.

One of the funniest photo videos I saw was on "How to fix a lens that has fungus." The guy took the lens, put it on a rock and hit it with a sledgehammer. Doesn't seem to be on YouTube; I saw it on a regular website.