A capitonym is a word that changes meaning (and sometimes pronunciation) based on whether the first letter is capitalized. Of course this only applies when the word is not the first in a sentence, where either usage would be capitalized. Gotta love English.
Same pronunciation, different meaning
China - a country
china - dishes
March - a month
march - a form of ambulation
Different pronunciation and meaning
Polish (POE lish)- having to do with Poland
polish (PAH lish)- the act of making something shiny (or the substance used to make it shiny)
Does this occur in any other language(s) besides English?