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.
genital genitalia genitally gentil gentle gently genteel gentile genteelly jointly
lanital genital sundial rental pinitol natal nidal notal entail fantail fontal cantal ventail cantala quantal quintal mannitol mental neonatal pintail cental dental
gent genet genette gentoo agent