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.
labour labor labra labara liber libri lobar libber lobber lubber lowbrow
tabour labour bur boar boor bora bore buhr bura burr bury labor rebore rebury tabor
lab labia lobo blab blabby elbow flab flabby slab