On orthography and certain homonyms

I suddenly came to realization that there is no logical reason for the orthographical (i.e. spelling, printing) reasons for the differences between "to", "two", and "too". Maybe I've been spending too much time reading pop lyrics on lyrics boards, but it seems to me that there's always a contextual link as to which word to use:
· "I'm coming, Frank, too" (I am also coming along, Frank)
· "I'm coming, Frank two" (a second "Frank" among friends?)
· "I'm coming Frank to" (this one had a better example in my head when I thought of it initially, damn lack of scrap paper!)

Gah, this all had better examples before I sat down here to write them...