"Is it pronounced tomato or tomato?"
I found this to be quite clever, since it's an oft repeated statement, but underscores that both pronunciations of the word "tomato" are "tomato", with no written distinction between the two. Written out with correct spelling, this statement just looks silly.
A responder replied with the following attempt to clarify:
" 'to-mato' or 'tom-ato' "
Apparently, this is supposedly clearly read as "to-may-to" vs. "tom-ah-to". This is because the word breaks determine the pronunciation such "mato" produces the "ay" sound as in "mako", as opposed to any other sound (such as the soft "a" sound of "matto"). Similarly, "ato" should be the "ah" sound as in... Well, there aren't really any analogous words.
In fact, even in the first example, you could probably have read things the other way around and put "to-mato" as being attributed to "to-mah-to", just as "mako" can be pronounced as "mey-ko" (more common) or "mah-ko".
Thus, breaking "tomato" into "to-mato" and "tom-ato" does little to clarify the dichotomous possibilities in pronunciation, but in fact merely does much to introduce an error in word emphasis. As any Grade 1 who has learned to clap out syllables will tell you, "tomato" is built from three syllables "to-ma-to". Whether you choose to pronounce that as "tuh-mey-toh" or "tuh-mah-toh", you can't drag along the "m" with the first syllable.
In the end, all you end up doing is breaking a three syllable word erroneously into two syllables. Now I don't know who Tom is, but I doubt he has anything to do with tomatoes.