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.
carful careful carefully carvel caravel caravelle gruffly corrival crevalle gruffily
fearful tearful carful cheerful jarful earful careful trayful refuel rueful barfly dareful purfle ireful deerfly direful farfel sorrowful weariful farfal
carafe carve corf curf curfew scarf scarify scarph