Imagine you are typing a URL into Firefox, or peraps a search string into Google, while others watch. You key in the first few letters, and suddenly…
Autocompleteophobia: the fear that your browser’s auto complete function will embarrass you.
Update: apparently, shift-delete is a Firefox user’s best friend. Thanks Bheesh.

Shift delete is a good thing… :) Start typing, and if you come upon a autocomplete you don’t want to see again, S-Del it!