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.
frost frowst frosty frowsty first frusta freest forest fairest fieriest firriest forestay ferocity furriest frisette verst verist verset verste farside varsity veriest feracity fireside foresaid foreside frizette
frost prost lyrist corset roast queerest forest roust wrest grist rust fairest roset roost frosty crust nearest hurst prest verst rest airest purist rearrest serest sourest dearest direst drest tourist tryst worst sheerest horst first curst merest verist crest wrist aerosat burst erst aurist arrest aorist barest prosit karst frowst jurist horste querist verste poorest verset purest rarest searest sorest surest diarist dourest durst trust worset wurst yarest
faros firs frass frise frisee froes frouzy frows frowsy frowzy froze furs