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.
frosty frowsty frost frowst first ferocity forestay frusta freest forest fairest varsity furriest firriest frisette fieriest feracity verst verist verset verste farside veriest fireside foresaid foreside frizette veracity voracity
frosty roast worst touristy serosity prosit morosity crusty roost roset roust russety rusty wristy aerosat forestay frost frowst frowsty varsity horst cariosity curiosity porosity prost torosity trusty christy
faros firs frass frise frisee froes frouzy frows frowsy frowzy froze furs