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.
furs fours feuars furies firs furrows furioso furious fears frise frays furze froes fores feres frows fiars frees fares frass fairs fries faros fires furzy ferias frowsy forays fraise frisee ferrous foresee faeries ferries fairies farrows foresaw friz ferreous vars virus verso viers verse veers varus varas vairs froze farce force farcy farci frizz vires vrows
burs knurs tours sours sieurs purs pours ours knaurs fours lours gaurs curs giaours hours furs yours