The "Hungarian phrasebook" sketch is one of my favourite bits of Monty Python. Part of episode 25 (second season, airdate 12/15/70), this sketch involves a maliciously misproduced English-Hungarian phrasebook. The phrase "my hovercraft is full of eels" is given as the English translation for the Hungarian phrase meaning "I want to buy some matches"....more hilariously, the Hungarian phrase meaning "Can you direct me to the station?" is translated by the English phrase "Please fondle my bum."
In channel usage, I use this phrase to mean "Huh?" or "I don't understand you." Typically, it elicits responses (taken from elsewhere in the sketch) such as "Drop your panties, Sir William, I cannot wait til lunchtime." or "Do you want to come back to my place, bouncy bouncy?" or "My nipples explode with delight." Elsewhere on the internet, this phrase has been adopted by people working in machine translation (like the people at Babelfish).
In the early 1990s, a company called LaserMaster put out a processor card to enhance the resolution of HP's extrememly popular LaserJet III printer. Possibly because of its role as a PostScript emulator, one of its error messages was "my hovercraft is full of eels." LaserMaster is now the ColorSpan corporation.