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.
tittup tittuppy
tittup tup getup cutup letup setup situp stoup stupa stupe
tittie titty tit vittate tutted fitted toited bitted tatted tutty pitted tutti gitted titi toit tatty tattoo tattie ditty ditto kitted dittoed tattooed totted witted