I knew about spring reverbs and tape echo, but until this morning, I'd never heard of oil-can delay, so I'm indebted to Joe for telling me about Tel-Ray: "Instead of tape, they used what looks like a tuna can filled with electrolytic oil. A tiny motor pulls a miniature rubber belt, spinning a flywheel armed with a pickup inside the can, acting like a recording head, sloshing it around in the oil to produce echo." These things were pretty mainstream in the early '60s - Tel-Ray licensed their designs to Fender, Vox and Gibson - so it seems extraordinary that I'd never heard of oil-can effects. The most popular myth about Tel-Ray is that the oil was carcinogenic and stuffed with PCBs. Geofex explain that the oil was made by Union Carbide, but isn't particularly toxic. A few years back, Bomb Factory released a Tel-Ray plugin for Pro Tools, but there doesn't seem to be any VST equivalent.