Pierre Abbat was the first to catch my mistaken identification of "pork" as a rhymeless word; he provided this fine set of culinary guidelines:
One never eats pork
With spoon or with fork
Or camel or stork
Or eagle or bat
Or coney or cat
Or rabbit or rat.
One may eat cricket
But not with a wicket.
I was led astray by Clement Wood, who is not always to be trusted. He claims that "pork" is pronounced with the /o/ (or maybe /oU/) of "foe," while "fork" (and all the other words that rhyme with it) is pronounced with the /O/ of "paw." Though my dictionary does list Wood's pronunciation of "pork," it's a secondary pronunciation; the primary one given in my dictionary, and the way I pronounce it, does indeed rhyme with "fork." Unfortunately, pronunciation varies so widely from place to place and even person to person that this sort of thing is bound to happen in any rhyming dictionary...
Don Monson provides a link to a very impressive online rhyming dictionary with a lot of cool features. Unfortunately its vocabulary is a little odd; for instance, it doesn't know the word "hieroglyph."
(Last updated: 10 January 1999)