Ok, so it's not as if you'll be able to pick them up at the local chippy, but circuit boards covered in oil may soon be available on a limited scale according to this post at PCW.
Apparently, Sheffield-based PC manufacturer Very-PC has announced that it'll soon be making servers submerged in oil available on the market.
While it doesn't sound entirely safe at first the theory behind the tech is sound in that, because oils like cooking oil are less conductive to electricity than other liquids (like water), systems can be submerged in them without risking a short.
The oil will, in theory, provide a powerless cooling system as the heated oil rises to the top, cools down, and then sinks to the bottom in a standard convection cycle.
Whether it'll be a success financially or not remains to be seen, but from a pure geeky perspective we have to admit we like the idea for it's crazy (and potentially tasty) applications.
We're always looking for the oddest mods around, so if this is tame by your standards then why not pop by the forum and put us straight