November 13, 2006
(This post is from my old, old, super old site. My views have changed over the years, hopefully my writing has improved, and there is now more than a handful of folks reading my site. Enjoy.)
Wikipedia: Five-second rule.
"The five-second rule is seldom invoked in the case of sticky foods, such as ice cream, cold cuts, or jelly beans which have been moistened, particularly if visibly dirty. It is also rarely used in cases of toast landing buttered-side-down."