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.
postop pasteup
estop stop misstop postop step stoop stope stoup stowp housetop isotope isotopy misstep dustup
post postie pst posset pest psst pasta piosity paste pastie pasty pesto posit piste poussette past pistou poised posada posed pesty