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.
whets wheats wets whits weets whats whites whiteys wats wots whities wits weds wades whids weeds waits wites watts wides wadies waddies whidahs whydahs widdies woodies wads
hets whets feats heights seats meats neats jets quiets setts gets peats pietas hits huts hats rets metes chats netts diets yetis teats shots sheets zetas betas vets fetes chits eats beets weets whats bets bahts etas meets poets tets haets hots beats pets nets getas keets quietus jetes metis lets fetas leets heats wheats cetes newts cheats whits foetus wets fets fetus sets duets sheds deets ghats suets phots shits shuts phuts yetts
whet wet weet what wheat whit white whitey whity