I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
setup situp stoup stupa stupe step stop steep stoop stowp steppe
getup letup setup tup cutup netop situp stoup stupa stupe tittup
set seat seta setae sett settee suet suety pseud pseudo