First time I went to a Python conference in SV, more than a decade ago, I kept hearing "Pie-thon" everywhere, and had no idea what the hell people were talking about.

I took me a solid half hour to at last understand this pie-thingy was Python... in my head I had always pronounced it the French way. Somewhat like "pee-ton", I don't know how to transcribe that "on" nasal sound... (googling "python prononciation en francais" should yield a soundtrack for the curious non-French speakers).